Here's my prediction:
Q2/Q3/Q4 see a 66% NVIDIA/34%ATi desktop marketshare ratio like we had last year.
Some will buy/keep ATi cards because they'll be cheaper. Most will buy NVIDIA cards because a. they do anyway due to name recognition b. even more so due to feature set.
ATi can go on about "open standards" for things like AA, PhysX, and 3d, but the public doesn't care about that- they just want the stuff.
Personally I'm counting the days till 3d Surround drivers are available- I just want to have it after playing with it at CES. I don't especially care ATi has opened up the drivers so 3rd party firms can develop for it- I want the tech NOW not in some hoped for future.
Same with PhysX. I want the option to use it NOW, not in the hoped for future. Even if they do some OpenCL physics games, I'll be able to use them as well. I want ALL physics accelerated games because they look better. The Terminator Salvation vid on YouTube pretty much nails why people should want PhysX:
It's pretty obvious which looks better and would be more fun to play.