Partly because I think you should stick by your predictions as long as they're still plausible, I still think that Mitt Romney has to be considered the favorite to win the GOP nomination. Matt, however, makes an interesting point about the biggest impediment Romney faces: the possibility that Huckabee will win in Iowa. Assuming (and I think this is right) that Huckabee has enough support to win Iowa but lacks the resources to be competitive in the front-loaded primaries even if he wins, the irony is that the most social conservative major candidate could hand the Republican nomination to the candidate least congenial to social conservatives. Although it's conceivable that Romney could survive a loss in Iowa, it would be hard to argue that he should be favored over Giuliani if it happens.
Of course, this kind of strange scenario is the result of the fact that there is a prominent hawkish social conservative in the race -- who's uncompetitive largely because of his personal conflicts with social conservative leaders. Between McCain being DOA and the late-entering plain vanilla southern conservative seemingly emulating Wesley Clark's 2004 campaign we have the current situation in which nobody seems logically capable of winning the Republican nomination. In that context, I still think Romney is the least illogical possibility.
--Scott Lemieux