The Celtics' next long-term center will probably come via a trade.
I don't buy that Ainge is clearing the decks to make Dwight Howard an offer when he becomes a free agent. Instead, I think he's going to use that cap space to acquire an elite big from a financially strapped/rebuilding franchise.
I think Howard is plan A. Over at Celticshub, they have Wyc talking about how when this ownership group first took over the C's they recognized that the overwhelming majority of championships were won by teams with a top 50 (all-time) player with 2 all-stars as supports. Hence the decision to rebuild the Toine-Pierce team and acquire assets for a future superstar acquisition.
With Garnett in the twilight of his superstar career, I believe the C's are going to be very aggressive about bringing in a new superstar in 2012 and using Rondo and Pierce as his supporting stars, and then using Pierce's money or expiring contract to bring in a new supporting star once Pierce hangs it up.
Dwight Howard is the easiest pitch of all the superstar options. His free agency lines up with our flexibility, we have a ready made spot for him on what would surely be a championship favorite (Howard-Rondo-Pierce with Ray and KG signing on as veteran role players for a final title run), his skill-set and age meshes beautifully with our star PG and his team has shish-kebobed its realistic contention hopes for the next several years, giving plenty of incentive for him to leave (very similar to the mistakes made by Minnesota with KG, Cleveland with LeBron and Toronto with Bosh).
After Howard, there aren't a lot of superstar bigs who project to become available to us. Griffin's not going to be available for awhile, Dirk's getting old and staying put, Pau isn't going anywhere, Duncan's done and no one else really qualifies as elite yet (Aldrige, Horford, Amare, Bosh, Boozer all 2nd tier guys).
If we strike out on Howard, we might go for the huge risk with Oden (definite elite potential), but I think the C's will go into a different mode and look to move Rondo and picks for superstar at one of the other positions (maybe Chris Paul).
It's either that or they think Rondo can blossom into a top-50 all-time guy in the right system (the Jeff Green move might be an indicator that they believe that, especially if they resign him for significant money).