These results aren't terribly surprising considering our large Radeon driver comparison from May (among many other Phoronix articles) still showed the Catalyst driver being far superior to the open-source classic Mesa and Gallium3D drivers in terms of performance and features. For only the older hardware generations (i.e. the Radeon X1000 series and older) is the performance becoming more competitive to the legacy Catalyst driver now that those open-source drivers have become near feature complete and mature.
The OpenGL performance results today show that the Gallium3D support for Llano is in the same relative situation as the Radeon HD 5000/6000 series in terms of maturity and performance. These results can also be compared on OpenBenchmarking.org against your systems by using 1108244-LI-LLANOGALL54.
Besides the performance lacking, compared to the Catalyst driver, the current open-source Linux driver lacks support for OpenGL 3/4 (it's still bound to OpenGL 2.1 compliance), OpenCL, PowerPlay, OverDrive, Hybrid CrossFire, and other features.
While the Llano support isn't particularly special under Linux at this point when not using the Catalyst driver, hopefully the display issues for Llano will be quickly worked out so that at least there will be a more pleasant "out of the box" experience rather than running into lock-ups and display corruption. It's likely too late for any Llano improvements to be back-ported into Ubuntu 11.10, so there the experience will be like the early days of Intel Sandy Bridge, but hopefully the support will be in good standing with Fedora 16. Of interest to Radeon Linux users might also be our look at the Radeon driver over the last four years.