None of these guys are running, no matter what. Jeb Bush might be a contender if he wasn't a Bush, but it's not entirely clear he would have even gotten this far if he hadn't been a Bush. Either way this country has had enough. We've already done two father and son teams (Adams, Bush). I can't foresee a third member of the same family becoming president in such a short time.
If I were a betting man, now with Barbour out and Daniels hesitating, I would say Jeb will announce in September. He passed on the Senate race for a reason and he's not going to wait until 2016 - because the world could end, the rapture could come. Jeb will be running in 2012, he was a decent 2 term governor, very popular in Florida, and he's got nothing else in his life left to do than run for president. His kids are grown up, out of rehab, hispanics are very popular now, and his wife and family will bring in the democratic hispanic vote. Jeb will be President in 2012 and win against Obama if he wants it. The Independents and Moderates love him.