VT Technology Blog: Windows Server vNext Technical Preview, Windows 10 Technical Preview, RSAT for Windows 10 TP, Windows 10 TP Guide (PDF)

Windows 10 Technical Preview designed for "PC experts", so it must be installed separately from the existing OS. The download files are 2,9 GB for 32-bit and 3,8 GB for 64-bit in size

Download Link:

Windows 10 Technical Preview
In order to download this preview, follow these steps:

Sign up for the Windows Insider Program
Read the system requirements
Click "Get the upgrade" and follow the instractions

What’s New in Active Directory Federation Services. Active Directory Federation Services (AD FS) in Windows Server Technical Preview includes new features that enable you to configure AD FS to authenticate users stored in Lightweight Directory Access Protocol (LDAP) directories. For more information, see Active Directory Federation Services Overview.

What's new for Hyper-V in the Technical Preview. This topic explains the new and changed functionality of the Hyper-V role in Windows Server Technical Preview, Client Hyper-V running on Windows 10 Technical Preview, and Microsoft Hyper-V Server Technical Preview.

Windows Defender Overview. Windows Defender is installed and enabled by default in Windows Server Technical Preview, but the user interface for Windows Defender is not installed. However, Windows Defender will update antimalware definitions and protect the computer without the user interface. If you need the user interface for Windows Defender, you can install it after the operating system installation by using the Add Roles and Features Wizard.

What's New in Remote Desktop Services in the Windows Server Technical Preview. For the Windows Server Technical Preview, the Remote Desktop Services team focused on improvements based on customer requests. We added support for OpenGL and OpenCL applications, and added MultiPoint Services as a new role in Windows Server.

What's New in Storage Services in Windows Server Technical Preview. This topic explains the new and changed functionality of Storage Services. An update in storage quality of service now enables you to create storage QoS policies on a Scale-Out File Server and assign them to one or more virtual disks on Hyper-V virtual machines. Storage Replica is a new feature that enables synchronous replication between servers for disaster recovery, as well as stretching of a failover cluster for high availability..

What's New in Failover Clustering in Windows Server Technical Preview. This topic explains the new and changed functionality of Failover Clustering. A Hyper-V or Scale-out File Server failover cluster can now easily be upgraded without any downtime or need to build a new cluster with nodes that are running Windows Server Technical Preview.

What's New in Web Application Proxy. Web Application Proxy now supports preauthentication for applications using the HTTP Basic protocol, wildcards in external URLS of applications, redirection from HTTP to HTTPS, use of pass-through authentication with HTTP applications, publishing of Remote Desktop Gateway apps, a new debug log, propagation of client IP addresses to backend applications, and improvements to the Administrator console.

What’s New in Windows PowerShell 5.0. Windows PowerShell 5.0 includes significant new features—including support for developing with classes, and new security features—that extend its use, improve its usability, and allow you to control and manage Windows-based environments more easily and comprehensively. Multiple new features in Windows PowerShell Desired State Configuration (DSC) are also described in this topic.
What's New in Networking in Windows Server Technical Preview. With this topic you can discover information about new networking technologies, such as Network Controller and Generic Routing Encapsulation (GRE) Tunneling, and new features for existing technologies, including IP Address Management (IPAM), DNS, and DHCP. Detailed information about what’s new is available for these networking technologies:

GRE Tunneling in Windows Server. This preview release introduces a new feature that enables Generic Routing Encapsulation (GRE) for the Windows Server Gateway.
What's New in IPAM in Windows Server Technical Preview. IPAM support for DNS is greatly enhanced.
What's New in DNS Server in Windows Server Technical Preview. The DNS Server role includes enhanced logging and a new policy based feature for DSN response management.
What's New in DNS Client in Windows Server Technical Preview. Window DNS Client provides enhanced support for computers with more than one network interface.
What's New in DHCP in Windows Server Technical Preview. The DHCP Server role no longer supports Network Access Protection (NAP).

What's New for Hyper-V in the Technical Preview

This topic explains the new and changed functionality of the Hyper-V role in Windows Server® Technical Preview, Client Hyper-V running on Windows 10® Technical Preview, and Microsoft Hyper-V Server® Technical Preview.

Rolling Hyper-V Cluster Upgrade

Storage quality of service (QoS)

Virtual Machine Configuration Version

New virtual machine configuration file format

Production checkpoints

Hyper-V Manager improvements

Integration Services delivered through Windows Update

Hot add and remove for network adapters and memory

Linux secure boot

Compatible with Connected Standby

RSAT for Windows 10 Technical Preview download link:

RSAT for Windows 10 Technical Preview
RSAT for Windows 10 Technical Preview enables IT admins to manage roles and features that are installed on computers that are running Windows Server Technical Preview from a remote computer that is running Windows 10 Technical Preview

Additional Information for Windows Server Technical Preview (vNext)

First preview build of Windows Server Next available to testers ZDNet

Hyper-V and the Windows Server Technical Preview  Ben Armstrong

Announcing availability of Windows Server Technical Preview and System Center Technical Preview Server & Cloud Blog

Testing the Windows 10 Preview in a Hyper-V Virtual Machine   petri

How to install Windows 10 Technical Preview on Microsoft Hyper-V in Windows 8.1 Pro mobileosgeek

Windows Server Technical Preview: FASTEST Way to Spin-Up Your Test Lab Environment in the Cloud with Microsoft Azure KeithMayer

Virtualization and some coffee: Scratching the surface of Networking in vNext  Kristian Nese

What's New in the Windows Server Next Preview WindowsITPro

Windows Server Technical Preview – Storage Survival Guide (links to articles, blogs, downloads) Jose Barreto

Hyper-V virtualization - setup and use in Windows 10 Windows 10 Forums

Windows 10 - Dual Boot with Windows 7 or 8   Windows 10 Forums

Hyper-V - Create and Use VHD of Windows 10 with Disk2VHD Windows 10 Forums

Getting started with Storage Replica in Windows Server Technical Preview TechNet

A first look at the Windows Server 10 Technical Preview ComputerWorld

Windows Server 10 Storage Replica Configuration and First Impressions   Clustering For Mere Mortals

What's New in Remote Desktop Services for the next version of Windows Server? Server & Tools

Storage Replica Guide Released for Windows Server Technical Preview   Server & Tools

Automated Server Setup in Windows Server 2012 and Windows 8, Part 1 WindowsITPro

Windows 10 Hyper-V Management WindowsITPro

The best new features in Windows Server 10 (so far) CITEworld

Console Improvements in the Windows 10 Technical Preview

Windows Server Technical Preview - New/Removed Windows Server Roles and Features MiCloud

First experiences with a rolling cluster upgrade of a lab Hyper-V Cluster (Technical Preview) Working Hard In IT

2015 Server OS Outlook: Cloudy, Chance Of Containers - InformationWeek

Windows 10 Preview - VMs Missing In Hyper-V Manager technet

Hot Add & Remove Static Memory in a Hyper-V vNext Virtual Machine Working Hard In IT

Announcing the MultiPoint Services Role in Window Server vNext Technical Preview Server & Tools

TechEd Europe: Windows vNext Hyper-V Backup and Restore PowerShell Scripts MSDN

What's New in Windows Server vNext Hyper-V Petri

Windows Server vNext Hyper-V Feature List Glossary Aidan Finn

First look at Windows Volume Replication Storage Replica in Windows Server ClusterMVP

Improvements for Remote Desktop Services in WinServ vNext WindowsITPro

Windows Server 10 New Cloud Witness Clustering For Mere Mortals

Windows Server 10 "Cloud Witness" in a failover cluster Clustering For Mere Mortals

RemoteFX vGPU Updates in Windows Server Next Server & Tools

Microsoft Demos Disaster Recovery Feature Slated for Windows Server RedmondMag

Hyper-V integration components are available through Windows Update Server & Tools

Network Access Protection in Windows Server vNext WindowsITPro

Hot-add/remove Memory on a Hyper-V VM in Technical Preview  vNiklas

Windows Server vNext Technical Preview: The first steps to software-defined everything ZDNet

Windows Server vNext Technical Preview: Screenshots ZDNet

First Impressions: Windows Server 10 Hyper-V Preview  Redmondmag

What's next for Microsoft's Windows Server 2016 ZDNet

Update 02/01/2015

From The Fire Hose:

"The Windows team recently shared information on the direction and delivery of Windows 10, and on the Server & Cloud Blog, you can learn more about what to expect from Windows Server and System Center this year.

“As we continue to advance the development of these products, we plan to release further previews through the remainder of 2015, with the final release in 2016,” writes the Microsoft Server and Cloud Platform Team.

The next preview is planned for this spring. “Windows Server will continue to share the same core technology as Windows and we will continue working together on solutions for our customers,” the team says. “In fact, the next version of System Center Configuration Manager, which delivers support for Windows 10, will ship in a timeframe that aligns with Windows.”

To read more, head over to the Server & Cloud Blog."