nandemoari writes "Not only will users be able to keep Windows Vista, but they'll be able to step back in time two generations, all the way to XP. "We will offer downgrade rights from Windows 7 to Windows XP in the same way we did with Windows Vista," a Microsoft rep said.
Insiders speculate that the right to use this time machine might be reserved for those purchasing licenses for only two versions of Windows 7 — Ultimate and Professional. However, that's not yet been confirmed."
"The algorithm to do that is extremely nasty. You might want to mug
someone with it."
-- M. Devine, Computer Science 340