It's been a while since the last Nouveau DDX driver update, but xf86-video-nouveau 1.0.8 was released this morning. This updated Nouveau X.Org driver comes with nearly two dozen changes.
Among the work to find with the xf86-video-nouveau 1.0.8 driver is attempting to fix the multi-monitor Zaphod mode, mandating DRI2 building (over DRI1), enabling support for a normal Optimus configuration, and other changes. The main change for end-users of this reverse-engineered Nouveau driver is likely the normal Optimus configuration support, of course you must be running all of the other latest software bits too.
More details can be found in the Nouveau release announcement