I believe McCain will get the nomination at this point. Eventhough many don't like him, he at least has some conservative views. I would put Romney at a close second, and he himself may even win.
I don't yet have strong feelings one way or another regarding the media's designated "front runners", before going in we all know Rudy has a clear liberal record, and McCain is widely disliked by the republican base. Romney is a bit of a clean slate, which will make him easily defined by his opponents, but if he has a good campaign he can easily overcome such things with a good solid message.
What I think doesn't matter anyway, I'm not even a republican, I just tend to vote for them in general elections.