It's nice to see such a large boost for Baker from the Globe compared to their last poll. Still, I want to see more polls of this race. While I think Baker is a good candidate and that Coakley is underwhelming, this is Massachusetts, one of the most liberal states in the nation, and Coakley seems like she has at least learned from some of the mistakes she made in 2010. Also, with Baker at only 38%, he has quite a way to go before I can say that he has a very good chance at winning. For the time being, I'm ranking this race at least Lean D.
Baker has the right beliefs to win in Masssachussets as a Republican, and he's probably one of the best recruits, but he's not a very good candidate. He's alright, but he has plenty of issues. But he's starting to make marked changes this time and that's promising.
Here's an article on his change in temperament.