The Windows Team Blog announced this evening a new Compatibility Utility for Windows 7 that will help customers still running applications designed for XP.
Windows XP Mode is specifically designed to help small businesses move to Windows 7. Windows XP Mode provides you with the flexibility to run many older productivity applications on a Windows 7 based PC.
All you need to do is to install suitable applications directly in Windows XP Mode which is a virtual Windows XP environment running under Windows Virtual PC. The applications will be published to the Windows 7 desktop and then you can run them directly from Windows 7.
You can learn more here
Paul Thurrott provides a gallery with additional screenshots showing how the software works and information about availability here. This seems like a really cool idea, in fact, it even includes a USB subsystem, so you are most likely able to use devices that are not compatible with Windows 7. Requirements right now call for a full Windows XP Professional license that will support the compatibility layer in Windows 7. Windows XP Mode and Windows Virtual PC will only be available to customers of Windows 7 Professional, Enterprise and Ultimate – Microsoft please change that policy.