At least Nvidia said it doesn't mind people creating open source drivers for their hardware (which is very good if you think about it), unlike for instance Microsoft, who recently vehemently opposed the intent of a third party to create open source drivers for their newly launched "Kinect".
As I understand it, Nvidia doesn't offer open-source drivers because they're afraid they might be infringing some patents which would show up in the source code.. (I heard many companies do this for same reason, don't we all love software-patents?) but then I don't know why they won't even release documentation since AMD doesn't have (serious) problems neither with the source code nor with releasing documentation about its hw.
The nvidia driver already does KMS (mode setting in the kernel). What it doesn't have is a framebuffer console driver, so it can't do the seamless switching thing that everyone seems to think 'KMS' means. Also, as I understood it, doesn't wayland rely on EGL rather than KMS/GEM specifically? Shouldn't nvidia supporting GL outside of X be enough?
Essentially, my point is that if we're going to ask the developers at nvidia to support things, we ought to ask for the actual things we want (EGL/fbdev etc) not implementation details from the open source drivers (KMS/GEM/TTM/DRI/mesa/gallium etc) which they will reject immediately, for obvious reasons.