I don't know anything about Hudson. But when I see stories like this (big bad corporate imposes their will on open source), I always think the drama queens (on both sides) are busy having "meetings" instead of doing actual work.
Want to fork? Then fork! You don't need anyone's permission. In this day of DVCS it's about two commands to fork back should relations improve. Using github is different only in degree, not in kind, from using a different IDE on your local machine. You don't have to have a holy war about it. If your development is better as a result you will win, if not you won't. It might be fun to throw a little tantrum, but it won't make the code any better.
If I'm a developer, especially a developer on a project for which I'm not getting paid, I'll do the development using whatever the hell tools I want, thanks. And if someone tells me I can't, frankly, it's not really up to them.