While VIA KMS + TTM support has been worked on for nearly two years, it still hasn't been proposed for merging to master. At the beginning of 2012 it looked like VIA KMS might be ready for a summer debut, but that never materialized.
In July there was the new OpenChrome release that prepared the X.Org driver for a VIA KMS world, but going on a half-year later, there's no push for the support to land. The problem was reiterated last month in another Phoronix article.
Development on the VIA KMS driver hasn't stalled, but it's just been very slow. There continues to be new VIA KMS commits for the branched kernel where the development has been happening, but this hardware driver is being worked on basically by a lone individual. James Simmons has been the one to work on the VIA KMS support and he's been pretty much doing all of this open-source VIA work alone.
Here's to hoping that we finally see VIA kernel mode-setting support in 2013... But based upon this current development pace, it's unlikely we will ever see a suitable Gallium3D driver for open-source VIA OpenGL acceleration before all of VIA's hardware becomes extinct.