Both Silver and my #'s indicate Gingrich squeaking out a narrow win over Ron Paul, with Romney in third a good bit further back. The only difference was that he had Perry beating Bachmann for fourth, but I agree with that based on the poll data that came out after I did my numbers. (Disclaimer: I'm just an amateur at this, though I've compared my predictions to the outcomes in past races and am only very slightly worse than the pros in my predictions.)
I just can't see Romney building momentum at this point. If Gingrich really does fall off (and I would be surprised if he holds it together), then either Bachmann and Perry have a second wind, or Ron Paul wins it. A Bachmann or Paul win would be a huge victory for the conservative base against the more liberal/big-government RINOs.
A Paul victory would completely eliminate Iowa as a player in future elections. After choosing Huckabee last cycle, choosing Paul this cycle would make all future candidates flee. No way would they bother to spend their money in Iowa.