Thinking about this more, I think that the killer feature for GitHub
is the network effect, not so much the specific DVCS used, etc.
However, I also think that spending a lot of effort on something that
doesn't actually get the project closer to releasing 0.9 doesn't seem
like a good use of energy right now. As long as we've got active
owners/committers on the project, I think migration would be a
distraction. Just MHO, of course.
Eli