I don't think he would. He would probably stay in Senate a little longer if he manages to win reelection in 2012, and might then possibly consider it.
If he is smart he will retire from the Senate in 2012 and then run for Governor in 2014 if Patrick has won reelection or Cahil or Baker only serve one term. If dems are smart they will run someone like Martin Meehan who can rally the base and win back any lost indies and even some Republicans. That would drive Brown out of the race for sure to avoid defeat.
Brown did not enter this race to be Senator he has his sites on the Governorship in 2014 in my opinion and this was just to raise his profile and get his favorables up. Well he has 60% favorability and is now well know in the state and even among the political class around the country.
I don't think this assessment is realistic. If Brown wants to run for governor, he'd have to be the most liberal member of the Republican caucus by a wide margin. Brown might want to run for governor in 2014, but I think his chances will be better if he loses next week.
As for Brown for president, no, though if Huckabee or Barbour gets the nomination, he might be in with a shot for veep. (And if he's reelected in 2012 he could run in 2016.)
