I never heard that Microsoft was going to quit making an OS X verions of Office. I have a hunch they are going to wait to upgrade it so the Vista version looks more and functions more like the mac version. The UI is so clunky in windows. They aren't going to fire a bunch of guys in programming when they are clearly making money selling to the Apple users. When you think about all the things microsoft creates and loses money on, they aren't going to stop making money because they want to stick it to Steve Jobs.
I don't see them making any significant changes to MS WORD anyway. How much better can you make a memo look?
You haven't looked at Office 2007 lately have you? MS majorly revamped the UI. I hate it but don't hold your breath expecting ANOTHER UI revamp anytime soon.