People who say Microsoft has backwards compatibility have never tried it!
Or they've had nothing but success.
A company I occasionally do work for dropped an old dos program that was in use since 1990 a couple years back. It was running just fine in Windows 7.
I've yet to see an old Windows program that wouldn't run. I've heard anecdotes, sure, but it's never been something I've actually encountered. The most I've ever had to do was check the "Run this program in compatibility mode for" box and pick an old version of Windows. That happens so infrequently I can't even recall the name of any of those programs.
What are these mysterious applications that run just fine under WINE on your Mac that don't run in Windows 7?