Microsoft is going to try their hardest to convince you to upgrade to Windows 7. In my opinion, the "Windows XP Mode" feature helps ease the transition if you have applications that require XP. This feature is an integrated copy of Windows XP Professional that allows you to run XP apps side-by-side with Win 7 apps. Windows XP Mode will be included with Windows 7 Professional, Enterprise, and Ultimate Editions.
If you don't have one of those three Windows 7 versions, you will be able to download Windows Virtual PC separately here. For more information about the Windows XP Mode feature in Windows 7 you can go here. If you are considering an ugprade to Windows 7 but still have applications that require Windows XP I would recommend exploring this option.
