* Adding coding activity to a mozillians.org profile will make contributing more attractive. Things to consider including are: A list of resolved bugs in bugzilla or else a ist of patches committed and authored would definitely help. Perhaps integration with open badges as well.
* Give mentors the tools to be successful -- a guide to when and how to contact someone to learn why they did or didn't complete a task, etc.
* Where are the high quality code contributors? Currently I think we wait for people to come to us. This may not be the highest of quality leads that are available. I think we should try to get an ad on StackOverflow to find new contributors. I think we can also look at cross-promotion opportunities inside Mozilla. For instance, the Mozilla Developer Network has an audience that covers people who aren't regular contributors and that could reach new people.