The Tech Report tried out Windows 7's XP Mode
>> Trying out Windows 7's XP Mode
With Business and Ultimate editions of Windows 7, Microsoft will offer a novel solution to backward-compatibility woes: Windows XP Mode. This free virtualization tool can work in the background to make Windows XP apps show up as parts of the Windows 7 desktop. TR blogger Cyril Kowaliski spent some quality time with XP Mode, and he's posted a detailed account—including installation tips and plenty of screenshots.
>> Trying out Windows 7's XP Mode