as a feature on windows 7....

how about a run as... feature where you can run as your favorite version of
windows... with compatibility and everything. total geek feature allowing
you to play 'tie fighter' or win xp pinball.... of course... at the click of
a button it becomes windows 7 again... no restart required. sort of a
high-end version of dosbox. you should have the bugs that ironed out. so
that you can do something like that. where's the profit in it? companies buy
it cuz they can still run peachtree accounting or their favorite tried and
true spreadsheet without retraining or having to buy some new version of
wordperfect.

Cheers!
Doc