I have an NV28 and nouveau loads fine, I even get 'direct rendering: Yes' reported, but that's where things end
The desktop feels like software rendering is used and any 3d app (as simple as glxgears) simply crashes the server. Fun stuff in other words :-P
Few things you'll need to change if you had the nvidia drivers from livna installed previously and you wish to try nouveau.
1. rename '/etc/ld.so.conf.d/nvidia-96xx.conf' into something like '/etc/ld.so.conf.d/nvidia-96xx.conf.disabled' (basically anything else that doesn't have a '.conf' suffix).
2. run /sbin/ldconfig (just to update the cache)
3. in your '/etc/X11/xorg.conf' replace 'ModulePath "/usr/lib/xorg/modules/extensions/nvidia"' with 'ModulePath "/usr/lib/xorg/modules/extensions"'
and of course do the usual changes to xorg.conf file, like changing the driver, loading glx and dri and setting the dri permissions. If all set properly and you have one of the 'lucky' cards, glxinfo should report direct rendering enabled. Some cards, primarily N4X, are able to run glxgears apparently. That should give you several hours of fun :-D
As for neighborlee's comment, nVidia stated that they neither support nor wish to stop the project. It's all legal. As for the reasoning behind the existence of the project, there are few that come to mind:
1. binary drivers are in violation with the GPL licence of the kernel (end-user usually doen't care that much)
2. binary drivers are black boxes that introduce an unknown in the kernel space. They can pose stability and security issues or at least uncertainties.
3. nVidia has been known for being extremely slow in dealing with serious bugs. There are several ones that have been known for over a year and there still isn't a plan to fix them (I particularly am affected by the 'black windows in compiz/beryl' one)
4. support for older cards is gradually dropped out.
You also get the problem with the official installation of the drivers messing up with the default setup of your system, but this isn't really a problem if you are using livna packages, for instance.