Windows XP mode is now available on Technet and MSDN.Windows XP Mode for Windows 7 makes it easy to install and run many of your Windows XP productivity applications directly from a Windows 7-based PC. It utilizes virtualization technology such as Windows Virtual PC to provide a Virtual Windows XP environment for Windows 7. Windows XP Mode provides a 32-bit Windows XP Professional Service Pack 3 (SP3) environment pre-loaded on a virtual hard disk.

Here are the instructions posted on technet
Note:
- You can use Windows Virtual PC to run Windows …

Finally after long wait Windows 7 RC and Windows Server 2008 R2 RC is now available for download on TechNet and MSDN.

The following downloads are available

Windows 7 Ultimate RC (x86) – DVD (English)
Windows 7 Ultimate RC (x64) – DVD (English)
Windows 7 RC Language Pack (x86) – DVD (English, French, German, Japanese, Spanish)
Windows 7 RC Language Pack (x64) – DVD (English, French, German, Japanese, Spanish)
Windows Automated Installation Kit for Windows 7 RC and Windows Server 2008 R2 RC (x86/x64/ia64) – DVD (English) …

The release notes for Windows Virtual PC Beta has been available and can be downloaded here
Here is what the download page reads
Windows Virtual PC (Beta) is the latest Microsoft virtualization technology that allows you to run many productivity applications on a virtual Windows environment, with a single click, directly from a Windows 7-based PC. For more information about Windows Virtual PC, please visit the Windows Virtual PC website. The Release notes provide important information you should know prior to installing and using Windows Virtual PC, including known issues. You should …

The Windows Live™ ID Sign-in Assistant 6.5 installs the Windows Live ID online provider for Windows® 7. By making it possible to link a Windows Live ID to a Windows 7 user account, this online provider helps enable Windows 7 applications to deliver great features like sharing documents, pictures, music, and video.
Benefits
Through the online provider, the Sign-in Assistant helps a Windows 7 application running on one computer identify and communicate with other computers that are associated with the same Windows Live ID. Just by linking your Windows Live ID to …

We’ve got .NET sample libraries and example for managed code developers to target Windows 7 new APIs!
The Windows 7 Beta SDK is a great source of documentation and examples for using these new sets of APIs. However, most of the examples are written in native code similar to Windows 7 APIs which are all native C, C++, and COM APIs, which makes the life of managed code developers a bit hard. For that reason, Microsoft created the Windows Vista Bridge project that makes it easier for managed code developers to …

The Windows platform has a broad ecosystem of products and partners that supports the platform. Displaying the Windows logo on your product represents a relationship and a shared commitment to quality between Microsoft and your company. Customers trust that seeing the Windows brand on your product ensures that it meets compatibility standards and performs well on the Windows platform. The Windows 7 Software Logo program is made up of policies and requirements that help ensure logo’d applications are easy to install and reliable on PCs running …

With Windows 7, the likely reason that Redmond didn’t support an XP upgrade is due to the amount of validation and testing required to support it to Microsoft’s standards.  With such an aggressive schedule, my opinion is that those testing hours can be better utilized for other things like compatibility and performance.  Nevertheless, IT admins aren’t completely out of options.
Vista had many way to be deployed and in-place XP upgrades were one of them.  Because of the small number of core differences between Vista and Windows 7, it makes sense …

Install this update to resolve issues with non-compatible applications for Windows 7 Beta. For complete details of this update, see Knowledge Base Article KB967062. After you install this item, you may have to restart your computer. This update is provided to you and licensed under the Windows 7 Prerelease License Terms.
Knowledge Base Article KB967062
Download the update  for x32 based systems here
Download the update  for x64 based systems here

Tip 15: Use a USB Key to Install Windows 7—Even on a Netbook
Putting the Windows 7 installation on a USB thumb drive has a few advantages—a small USB key is much more convenient for carrying around than a DVD, the OS will actually install much faster, and you can use a USB key to install Windows 7 on systems that do not have a DVD drive, such as a netbook. In fact, you can even install Windows 7 on netbooks that have fairly modest hardware. Dennis Chung, an IT Pro …

The Windows Live ID Sign-in Assistant 6.5 (Beta) installs the Windows Live ID online provider for Windows 7. This provider enables linking a Windows Live ID to a Windows 7 user account.
The Windows Live™ ID Sign-in Assistant 6.5 (Beta) installs the Windows Live ID online provider for Windows® 7. By making it possible to link a Windows Live ID to a Windows 7 user account, this online provider helps enable Windows 7 applications to deliver great features like sharing documents, pictures, music, and video.
Benefits Through …