In this new post to his blog, Christian wonders if forking the 1.x branch of Symfony to create a 1.5 version is a real possibility.

The idea of forking came up. But is this really going to happen? And does it make any sense at all? What would be the benefit of forking symfony 1.4 and continuing development of the 1.x branch?

He suggests that it might be worth it because the branch is currently stable, it has a proven track record, there's already several plugins available and there's a comfort level among developers using it. He still asks the "why?" question, though:

Not switching to Symfony2 would essentially mean that you accept these flaws [in 1.x]. Now even if I don’t agree I can not see a reason to argue against this. Being pragmatic is not a bad thing as such.