As we've discussed before, Rudy is likely to pick up Florida and California, and really put a stranglehold on McCain and Romney.
I think that's far from inevitable. Giuliani's leads in FL and CA are hardly insurmountable. His leads over Romney in those two states aren't really any bigger than his lead over Romney nationally. If Romney crushes Giuliani in the pre-Florida states, he could get a national bounce out of that of something like 15-20 points. Then he writes himself a big check so he can outspend Giuliani on advertising in Florida to make up any remaining gap in the polls there.
If he wins Florida, I think he'll be the frontrunner in CA, and the frontrunner to win Feb. 5th overall. In fact, I think whoever wins Florida will probably be the big favorite to win Feb. 5th and the nomination.