In fact I have a lot of developers asking for design help (and luckily vice versa)
The format I use is a little more free form and it's curated which I hear a lot of people say help a lot.
Plus projects are fresh.
I have also tried to involve myself in OSP over the years.
The problem at least from my experience was that while developers have a clear process on how to work together amongst themselves. While they have created their own lingo. It doesn't really include the design process (unless they like me want to learn how to use GitHub) and how that ties into development.
There is clearly a disconnect between the two disciplines and I have yet to find a tool to allow for easy transcendence. You can't in my experience use the github principles for versioning of design, since iteration works completely different for most designers.
I have a couple of ideas of how that could be done, maybe I should start a WH project :)