Can't tell you how much I would love fully featured open source drivers from the GPU guys, for their latest (even if not greatest :)) 3D cards for linux. Right now, I am writing this on a laptop which has integrated nvidia GPU. It's Geforce 6150 Go. Decent, but not great. But hey, it's pretty good for my budget.
The only practical problem with the nVidia drivers is that whenever I shut down X, the whole screen goes garbled and starts displaying weird colors. Thanks to the Ctrl-Alt-F6/7 trick, I am able to restore it back to normal, but it shows the lack of maturity of the drivers. The problems associated with trying to reach nVidia to resolve issues with their proprietary drivers are legendary.
I just hope that the nouveau guys can get 3D up and running ASAP. AMD/ATI has done a very good job here by providing docs so that we can write our own drivers. Right now, I am pretty sure that my next computer will certainly have intel or ATi graphics in it. Besides I am secretly hoping that intel is able to resist the temptation to go proprietary only for Larrabee.
The real big push in the driver space is going to come because the GPGPU guys (like me) want more flexibility in the drivers. It is a very important piece in the software stack and the features provided by the present day drivers are simply not enough if GPGPU has to live up to its true potential. Want an example? There are many.
1) I want the data to directly DMA'ed to/from GPU memory instead of being streamed via system RAM.
2) I want the GPU handling API to signal a condition variable (pthreads).
3) I want the GPU to absolutely not perform any graphics tasks and instead leave them to the integrated graphics.
4) Related to 2. Anybody who's going to the trouble of porting stuff to GPU's obviously wants his CPU to to be maxed out as well. With parallel solutions dime a dozen, he would obviously want some support for his solution from API, as in 2 above.
While I don't expect even the upcoming open-source ATI drivers to have features wished for by me, their open source credentials ensure that I can hack them myself if I want to.
I just hope that the RadeonHD driver team is able to deliver quickly and I am praying that nouveau team succeeds as well.