No, New Vegas works fine. It's also remarkably bug-free by now. Only Old World Blues had issues when I played it (the game would crash on auto-travel).
Does the same apply to New Vegas? Hope not!
Managed to get Fallout 3 working on 64bit W7. Turns out my earlier confidence in it was premature and it would freeze after 10 mins or so.
If anyone is struggling with this or is unsure about grabbing it, it IS possible, but you just have to put yourself through a load of faff