I am happy with an API for GitHub status which provides a callback to an user defined function.

I don't know how alwaysUseGithubRepo="user/repo" will work with Buildbot installations used for multiple independent project. In this case, the "project" and "category" properties are also required.
 
In the same direction as your suggestions for alwaysUseGithubRepo="user/repo", I am also interested in providing a way to use GitHubStatus plugin with minimum configuration, so that small/simple project will not require to much plumbing with Buildbot.
For this usecase alwaysUseGithubRepo should help.

Regarding transition to 0.9.0, I will be happy to continue to maintain this plugin and commit time to update it for 0.9.0.