Edmund Andrews links to John M. Berry's article on Alan Simpson and Social Security, and asks "Will Alan Simpson torpedo Obama's deficit commission?"
Well, I suppose he might, if the goal of the commission was to reach a bipartisan agreement to reduce the deficit. I think that's unlikely; the commission is structured so that Republicans can veto anything, and I don't think Republicans are particularly interested in slashing the deficit -- they might go for reduced spending on some things, especially if they didn't have to take the blame, but there's no evidence at all that Republicans would support anything on taxes that would reduce the deficit, or take specific responsibility for cuts to anything significant.
Instead, I think the goal of the commission is to polish Obama's reputation for fighting deficits without, uh, actually doing any deficit-cutting. Unpacking this one is rather tricky...given the economic and budget team Obama has assembled, I suspect Obama actually is a bit of a deficit hawk. However, economists are probably close to unanimous that deficit cutting during the recession would have been a disaster, and most probably believe that larger, not smaller, deficits are called for still. Against that are Republicans who are going to criticize Obama whatever he does, and deficit scolds (including some Democrats in Congress) who believe that cutting deficits should be a policy goal, rather than treating deficits as a means to the end of a growing, healthy economy. The commission, as far as I could see, was a way to hold off that latter group while waiting for the economy to recover -- and there was always a chance that it would produce some information about the priorities of various players, which might be useful when the real negotiations take place in 2011 or 2012 or later.
What I'd say about Alan Simpson is two things: he's always been (in my opinion, I guess) a very partisan guy, but also one who is capable of saying goofy things -- perhaps not as goofy as Joe Biden, but he's not exactly a message discipline kind of pol. Washington being Washington, that often gets confused with a sense of humor, and also is sometimes confused with a lack of partisanship.
So my best guess on Simpson is that, no, he won't sink the commission -- but it doesn't really matter, because the commission isn't designed to float in the first place.