Earlier quoted context omitted.
Yep. GitHub has an API so that could be useful. I'm sure people will want to discuss projects and ask questions, especially with the admin or creator. Also, I was thinking that a widget would be good, so existing sites could let its users know it's looking for development help. These sites would build up a record of people that have contributed code.
Now, when you say "discuss projects and ask questions" are you thinking wiki interface for discussions, maybe a sort of GetSatisfaction type idea for discussions, maybe with voting? Even Github lacks some neat discussion systems that might be nice to see somewhere.
Provide a realtime chat if you can, ie like: https://github.com/isaacsu/twich Give it a timetable so each project has a set time for participants to chat, (the project in question is displayed at the top of a page.) You can also record chats, and offer multiple rooms.
Maybe a Q&A archive for each project, along the lines of http://forum.twich.me/ or http://formspring.me