I lean more towards pessimistic. There's a good chance that Assad is out of Damascus within a few months, but the sectarian civil war continues for years after that. It's not like Libya, which didn't have nearly as much of a sectarian component in the uprising.
Btw, Assad is clearing the way for an Alawite mini-state if it comes to that:
http://www.foreignpolicy.com/articles/2012/07/27/alawistanBut even if that happens, my guess is that the two sides keep killing each other for a long time to come, probably years, a la Iraq.