Well, they certainly do subscribe to MS goals and visions and release the driver in a way that's appropriate for Windows platform.
Having said that, nVidia is by far the best (the only actually) solution for Linux. We run bloody flash animations and videos 24/7 on cheap atoms - if it wasn't for nVidia ION we couldn't be anywhere near to being competitive. Although it would be nice to have a built-in support, it's not exactly rocket science to rebuild the modules for different kernel. We do it all the time - nVidia driver install provides the infrustructure (precompiled kernel interfaces), we build it once, then distribute via yum/rpm to hundreds of client sites via nightly yum update, reboot and everything else taken care of automatically. Never failed us.