Once you have a stable release people should use that branch
Sadly impractical. It would force never backporting fixes to stable branches, amongst other things, because otherwise you'll have some people using 'the stable branch', and some people using 'the stable branch plus some fixes', and it doesn't solve anything, you actually risk fragmenting things worse.
At least with milestone releases, you can locate issues by version. (It's hard enough to get people to actually say what version they have. Very often people can't even get that right. I shudder to imagine them trying to post by revision; at least SVN has revision numbers - Github doesn't last I saw.)
it would be better to have them post to branches that you can review and merge back if you accept the fix.
Aside from the small fact that trying to merge the disparate branches would be an absolute nightmare. SMF from whence we came, has a very complex nature of inter-dependence. You can't change one thing without having it spread out throughout. Invariably a bug fix requires changes in more than one place, making it rather difficult to actually do this, especially while new things are being coded around it.
If the code were more modular, perhaps it would be feasible, but certainly not the way it is right now.
Thing is, you haven't convinced me why it would be good to open up the repo, you've just told me how I'd use the result, not why it would be good for me, or for Wedge for that matter. I'm happy to review bug fixes and so on, but I'll be absolutely damned if I accept patches in a manner consistent with Github, where someone creates what amounts to a fork branch, commits their changes and magically expects me to commit it. It promotes the expectation that work will be accepted, even when it really won't.
The number of commits accepted from other people thus far is still in single digits. I do not expect that to change as a trend, because we are very protective of our work thus far, and the culture engendered by Github et al, whereby changes are committed into a repo that makes it 'trivial' to incorporate change is actually in my mind a very bad idea. It makes people complacent about including changes, rather than reviewing and putting in the effort to include it.
You see, in all my experience of development, the actually successful projects survive and thrive because they have a specific culture. They have a culture that is a fusion of a meritocracy and a benevolent dictatorship. In other words, people at the top that make the decisions, and people tend to have their opinion listened to more thoroughly if they've proven that they aren't wasting time/effort. If someone consistently posts poor code, I'm not exactly going to be enthusiastic about accepting their bug fixes, now, am I? Yet, social coding explicitly encourages contribution, but it doesn't encourage *good* contribution.
Putting it in the forum is actually a much better barometer for the quality of something in my experience.
Also, see
http://wedge.org/pub/off/6923/plugin-development/ which in hindsight is probably a better place for this discussion because we're now so far off topic from what I hoped to discuss...
I don't think it really matters, there's been enough people that have misunderstood the point of what I'm getting at here judging by some of the responses here, not to mention some of the private responses I've had, that I'm actually inclined to leave it in despite my gut instinct.