I am not a huge Beltre fan, but this is a GREAT deal. To get him for one year is huge. He now has a year to prove he can play, and more importantly hit, in Boston.
This also leaves the door open for them to go after Gonzalez during the season (Beltre on a one year deal could end up being a nice part of a three-way trade), or go after Mauer next season, with less money on the books.