Hi Chris and Cafe!
I've sent Chris an email couple days ago, this is another one to have haskell-cafe CCed in order to request maintainership of protocol-buffers package.
Stefan Wehr actually tried to contact Chris long time ago, and thus you can see current "riak" package depends upon protocol-buffers-fork package, created to add support for GHC 7.8.
I'd like to incorporate work from protocol-buffers-fork, add support for GHC 7.10, and also move project to GitHub and add some README with at least basic tutorial.