People are floating a lot of names for 2012. Sarah Palin, Tim Pawlenty, Mitt Romney, Mike Huckabee. There isn't a lot of impact behind any of the names -- I happen to think Mitt Romney is going to emerge the victor as the conservative base splits amongst Palin and Huckabee.
This week there's been rumors about a Lou Dobbs run, and there's also this week Glenn Beck's continuing his 9/12 Project insanity by becoming a "Community Organizer" (har har it's so meta). If these folks enter the race, I'm willing to put all my money behind Lou Dobbs being the Republican Candidate. He comes across more genuine than Romney, smarter than Palin, more memorable than Pawlenty, more marketable than Huckabee, and more stable than Beck. He's still a very solid conservative without getting trapped in too many of the excessive crazy that all of the other candidates have on the record (except Pawlenty -- Palin's desire to be rid of witches, Romney's "double Guantanamo", Huckabee's HIV-Positive quarantine camps, and basically everything Glenn Beck says). Lou Dobbs can appear on The Daily Show or MSNBC and still be treated with a respect that very few of the other candidates can still muster.
I'm not going to make any forecasts until a year before the primaries, since I love forecasting and I love being wrong. But I will say that having to watch a Dobbs-Beck debate moderated by Brit Hume is the sort of thing that makes me think the Mayan Calendar thing might be right...