The PPA include 64 and 32 bit versions of all the packages (indeed glxinfo works fine). The problem is that when you want to use a 32 bit game (i.e. games you download from 3rd party sites. Games from Ubuntu archives should always be 64 bit) on a 64 bit system you have to also install 32 bit mesa, but that's not easy to do on natty. It will be easier on oneiric (I'd suggest to try it...).
No announcement yet.
Updated and Optimized Ubuntu Free Graphics Drivers