Well there's this from Cnet:
More on Windows 7's 'XP Mode' | Beyond Binary - CNET News At its core, XP mode consists of two things, the Windows Virtual PC engine and a licensed copy of Windows XP Service Pack 3 as a packaged virtual machine. Although neither piece will be included in the Windows 7 box, XP Mode will be a free download for those who have a license to Windows 7 Professional, Windows 7 Enterprise, or Windows 7 Ultimate.
And I read that those with separate copies of XP will not have to buy the Pro Or Ultimate version of Windows 7 to use XP Mode if they wish to.
So you're saying that the XP download is an altered version of it? Are you sure about that? And that I couldn't even install an older version of XP that I already own and use my new Windows 7 license number with it? Because apparently even XP Mode users do have to enter the Windows 7 license a second time when they install XP in XP Mode.