If BK really needed to trade these two, I would not dumo them for an old Paul Pierce. If we really needed another 3 position why not try this trade, http://espn.go.com/nba/tradeMachine?tradeId=c9z4jky. I personally think both teams get what they want, and now the BKN would have Wallace and Granger who can play both the 3 and 4 and literally can switch positions during the game. If we had to play Miami in the Playoffs, I would feel a lot better with Granger guarding Lebron vs. Wallace.
Also, like Hump, Granger only has 1 year left on his contract. If this trade actually took place later today, I would not at all be surprised.