Yesterday's patch-set builds upon another set of 19 patches he published this weekend (Remove all uses of the register mask) which affected about 800 lines of code.
The intent of this work by Marek is to provide "a series of cleanups I am going to make to improve the horribly over-engineered and slow state management of r600g."
The register mask removal was a prerequiste to this current work, which in this latest series tidies up the driver a bit while also adding a new mechanism for emitting states, which is inspired by the older R300g driver. Marek says this new mechanism is simple yet robust. He's also made various other low-level changes to R600g.
This R600g work should end up being part of Mesa 8.1. For those wanting to dig into more details about this work, the patch-set from yesterday can currently be found on the mailing list.
The open-source ATI/AMD Radeon Linux driver code still has a ways to catch-up to the Catalyst driver. But if you're interested in boosting your graphics performance, try the 2D tiling code and enabling PCI Express 2.0 support.