I really think we need to do something with Wally's contract. Obviously, the best case scenario is getting Bosh or Butler, but the chances of either of those two things happening are slim. On the other hand, trading for either someone like Stephen Jackson or Gerald Wallace to give us more size in the backcourt or a solid big man seems quite possible with Wally's expiring contract. I really don't see any reason not to trade, especially if we expect Wally to get bought out of his contract and come back.
Right now, I think you have to give a slight advantage to the Celtics, especially if they have homecourt advantage in a playoff series. However, picking up a solid wing or big man probably gets us to about even and obviously getting Butler or Bosh without losing any of the starting 5 or Andy probably puts us way over the top.
Not to get off topic, butthere is part of me that wants us to not go for the all star caliber player simply to see LeBron be one of the only players to ever win a championship without another all star on the team (it doesn't appear that any other Cav will make it based on the early voting). If you go back through the years, Jordan had Pippen, Shaq had Kobe, the Spurs had multiple all stars, the Pistons I think did too, Heat had Wade and Shaq, Rockets had Clyde and Hakeem, 80's Pistons had Dumars and Thomas, etc etc etc. You can't find one team that only had one player considered to be a star in this league, though you can make a case for Mo and Z. Of course, there is no guarantee we win the 'ship with the current group of players.