Bass is one of the best big man jump shooters in the league. Add in his defensive ability, athleticism, and decent rebounding (below par but serviceable), and you have a player that's a great fit in the Magic's system.
That said, I don't think they need him now that they've gotten Ryan Anderson. Anderson gives them a backup power forward with a very impressive jump shot. He was a great acquisition in the Vince Carter trade.
What Orlando needs to do now is to sign a replacement for Marcin Gortat. They need a big man who can back up Dwight Howard, rather than someone who can play alongside him.