I've just updated the R600Todo page, with some LLVM and Compute tasks. I'll try to keep this page updated and add more tasks as I think of them.
These tasks are a great way to get started on GPU driver development, so if you are interested, pick a task and start hacking! Also, let me know what you are working on so I can update the page. If you have any questions about any of these stop by #radeon or #dri-devel on irc.freenode.net and ask.