I know, another thread... However looking at the iOS features of Mountain Lion coming again to Macs, is there even slightest support for professionals in Apple's future?
Anyway, I am happy I bought 2010 Mac Pro. I am good to go for couple of years and have time to think what to do if...
Just because it's not publicized doesn't mean it's not there.
Mountain Lion contains a lot of new goodies for Pro apps under the hood, especially video apps. And as already has been noted, there are driver enhancements for Pro GPUs.
I have an NDA, so I can't really talk about it, but what Apple publicizes isn't necessarily all the changes.