My Bet on the Nobel
The best objective measure of scientific influence is citations. I have heard all the objections to such crude measures, and I will admit that citation rankings are imperfect. But subjective judgments are imperfect too, and often much more so.
Moreover, as a purely predictive matter, highly cited economists usually get the prize eventually. In this old citation ranking, the top five most cited economists are all Nobelists. As of today, the prize has gone to more than half of the top 30 (and some of the others may win it in the future).
Based on citations, who is in line to get the prize? In that old ranking, the top two on the list who have not yet won the prize are Fama and Feldstein. In this somewhat more recent citation ranking, the top two economists are Fama and Barro. In this most recent ranking, the top two are Barro and Shleifer.
Thus, if I had to bet a dollar on this year's prize, I would put it on Fama, Feldstein, or Barro. Andrei, who is still in his 40s, will have to wait a few more years. But as long as he lives long enough, he is a sure thing.
Update: Here are the predictions of Thomson Scientific, the guys who maintain one of the citation databases.
Update 2: None of my bets won, although I remain confident that they will in the years to come. FYI, in this citation ranking, Eric Maskin is number 106 and Roger Myerson is number 96.