Its been stated before in interviews with NVIDIA developers that their drivers do share a common code base between all platforms. And as much as i would like to see their own 100% open source driver, I do understand there is likely licensing issues that prohibits that, as well as competitive concerns in releasing the source.
Mostly however I hope they keep their promise of 'not helping but nor hindering' the Nouveau project (I mean obviously more on the nor hindering part) Plus I how they would be of any gain by trying to hinder? other than causing a bad relations shit storm amongst the already divided opinions.
As for Noveau, it seems from my own and other experiences from Arch Linux forums that its as good as if not better than the xorg-nv driver anyway.
Seems they win mostly by not having to spend any development time on it.

"If you think the problems we create are bad, just wait until you see our solutions"
-Government Demotivator http://despair.com/government.html/

am i the only one thinking.. this is a university surely there is the talent to provide their own hosted and competitive system?