This is just for hosting. Everything else: the reviews, PRs, bug reports are staying where they are.
I am not sure moving to github as such gives it any advantage if they don't make use of the remaining infrastructure.
The model Rust uses, I think, is the best way to make use of github and it's features.
If I'm right, one of the advantages of this move is that llvm will finally switch over to using Git as its main version control system, and get rid of svn altogether.
No, svn will still be supported since github has it for all its repos.
Can you describe the model rust uses or point me to a link?