Closed drivers are bad, but getting open drivers seems to be much harder than getting the open UI. UI can be designed from scratch by the community. Drivers require either full hardware specs (non existent in the vast majority of cases), or reverse engineering. The second does happen, but slowly and painfully:

https://gitorious.org/freedreno/pages/Home
http://www.youtube.com/watch?v=3A6jnBQ2L-A

http://limadriver.org/
http://www.youtube.com/watch?v=7Bi8kT2e3f0