Urban Terror is pretty much the same story as the other ioquake3-based benchmarks.
When running the more visually intensive Xonotic OpenGL game, the Nouveau driver was surprisingly still able to compete with the NVIDIA driver when both drivers were controlling the graphics processor and video memory at the same frequencies.
While it's nice to see the Nouveau driver can be rather competitive with the NVIDIA binary driver when both Linux GPU drivers are controlling the hardware at the lower boot frequencies for the graphics cards, don't get too happy just yet. The lack of proper re-clocking support within the Nouveau driver is still quite troubling and we may see it improved slightly with the Linux 3.8 kernel, but it won't be for all supported GeForce GPUs and it's unlikely to be dynamic re-clocking by default, such as what's done by the NVIDIA driver with PowerMizer. So even if you're able to run up your core and memory frequencies in a sane and stable manner, when not under load you'll likely still be burning through more energy than with the NVIDIA driver.
Most of the tests in this article are also rather basic GL2 games that aren't too demanding on OpenGL compared to game engines like Unigine and Source. The NVIDIA binary driver supports OpenGL 3.3/4.3 while the Nouveau driver is at OpenGL 3.0. The Nouveau driver also misses other important features like VDPAU using the dedicated PureVideo HD video engine, multi-GPU SLI, 3D Vision, etc. As I mentioned in the introduction to this article, the Nouveau stack found in Ubuntu 12.10 wasn't even stable for some of the older (GeForce 8) graphics cards. On the newer-end, the Fermi/Kepler support is still maturing too. Regardless, at least this community-based Nouveau driver reverse-engineering project continues to make great progress.
Stay tuned for more Nouveau benchmarks from Linux 3.7 + Mesa 9.1-devel.