I'm not going to put a lot of stock in markets that see Biden as the most likely nominee -- they have Kerry at 9%, after all -- but this does seem to be the consensus. And perhaps I've been buttered up by the fairly dismal alternatives being offered, but like Steve I find Biden a surprisingly decent option. At a minimum, he's strongly preferable to Kaine or Bayh, infinitely preferable to Nunn or Hagel, and clearly behind (among vaguely viable candidates) only Sebelius and Reed.
Cohn has a good roundup of the strengths (most domestic policy, brains, legislative accomplishments, crucial role in the immensely important defeat of Bork) and weaknesses (gaffe prone, his botching of the Thomas hearings.) It is, I think, fair to note that a Delaware senator's support for the bankruptcy bill is as inevitable as candidates in the Iowa caucuses supporting ethanol. I wouldn't give Biden a pass, exactly, but Bayh cast the same vote with considerably less excuse. To the list of defects, though, I would add a lack of executive experience and his initial support for the invasion of Iraq (although, again, on the latter issue his problems are much less severe than Bayh's). On the other hand, while it might be a minor political liability, I think the old "plagiarism" charges are of little substantive significance -- the idea of "plagiarism" in a context where nobody expects you to write your own words in the first place is nonsensical.
If I thought the VP choice should be determined by political considerations, I would pass; his penchant for saying silly things and hailing from a small, safe state would rule him out. Since I think the VP pick should be primarily substantive, however, I think he would be decent -- he could play a constructive policy role comparable to Gore and is considerably more progressive than most of his assumed rivals for the job. He wouldn't be at the top of my list, but of the InTrade top 3 he's the best by a huge margin.
--Scott Lemieux