To recap, the Red Sox and Padres agreed in principle to an Adrian Gonzalez trade on Thursday night. Gonzalez was set to become a free agent after the 2011 season, and the Red Sox were given until 2pm ET Sunday afternoon to work out a contract extension. No such contract extension was reached, but there remained a possibility that the trade could still go down anyway, and, now, it has.
Unclear is whether a contract extension agreement has been reached, but if one hasn't, then the Red Sox are presumably confident that they can get something done with Gonzalez before he becomes a free agent. They're still trading Casey Kelly, Anthony Rizzo, Reymond Fuentes, and a fourth player to the Padres, and that would be a hefty load to give up for one year of a player.
The 28-year-old Gonzalez has been one of the better hitters in baseball over the last few seasons despite spending half his time in an extreme pitcher-friendly ballpark, and his good defense and power to all fields should make him a superstar in Boston.