Well, it seems like Nvidia has put the cards on the table and will not provide open source drivers for Linux. It will continue to ship the pretty good but closed source binary drivers for the time being. ATI/AMD started a few months ago to provide the community with documentation on their hardware. I used to tell my friends/family that if they wanted good display drivers they should get a nvidia card. I am changing my advocacy to ATI/AMD as of today. I am not doing this for "religious" reasons, but with plain economics in mind. If I have the choice, and I do, between open source and closed source I choose open source, because my experience shows that binary drivers will get obsolete some day while open source rarely do.
My new endorcement: Buy ATI/AMD cards.