Posted on the Microsoft Windows blog today is an official announcement of Windows XP Mode in Windows 7.

Specifically designed to help businesses move to the new version of Windows and still be able to run any old legacy applications.
All you have to do is install the applications in a Windows XP environment running in Windows Virtual PC. When launched the applications will publish to the Windows 7 desktop and run directly in Windows 7.

This is good news for small businesses stuck with running old productivity applications that do not work with newer versions of Windows.
The bad news, it doesn’t apply to Vista if you were unlucky enough to buy that, and it only applies to Windows 7 Pro and Ultimate. In other words the most expensive versions of the Hydra headed Windows 7.

Not as elegant a solution as Rosetta on Intel Macs that allowed legacy PPC applications to run seamlessly on the new architecture. And OS X provided an almost invisible way of running legacy OS9 and older applications.