If everyone else thinks that MyFaces 1.1 is "finished" enough that we're only doing bug fixes, then having it as a branch is fine with me. I don't see any technical reasons not to do it this way. It looks like we have 75 unresolved bugs filed against core, but those with a vested interest in having them fixed will eventually submit patches.
I'm curious to know how many committers are going to "jump ship" to 1.2 as soon as a repository is available, although I'm not suggesting this should be a factor in creating the branch.