wow... I voted Oden

It'd be great to get Howard, I can't stand the guy and his faux smile, but he'd look great next to Rondo.
Nenad is not the future, but I can see him in green next year, resigning for 1 year, or long term. In the 2012 trade deadline he could either be a nice expiring or a trading chip.
Through draftexpress and nbadraft.net I can't see a good prospect available when the Celtics make their pick. Keith Benson could be a building block for a future trade package, or a backup. The only seven-footers available this or next year are young prospects playing in Europe (Musli, Nogueira...) and the Celtics better not waste a first round pick in guys who will probably stay in Europe for a couple or three more years.
I hope Danny sends back the pick to the Cavs next year to bring back Semih. If he wants to stay in the NBA he can be a good backup, and next year he could save minutes for the O'Neal brothers. If the C's get #18 this year, they will try to win another one, so I don't think they are retiring.
Murphy can't play the 5 consistently. Of course he can do it for a while, just like Scal did it, but I think he could stay to play backup 4 next year if Baby is gone. BBD could go in a sign-and-trade, or sign as a free agent for whatever team is willing to pay him and let him "shine".
About Oden, it seems like the Blazers are extending the qualifying offer next june, so that takes him off the table. There could be a way, say they sign-and-trade Davis for aroun 5 mil and package him with the Marquis exception for the Oden expiring 8 mil contract. I don't see how Portland would like BBD that much, but it could work out fine for the Celtics.
If JO is retiring after this season, they could also work out a trade of JO+ trade exception + cash in order to get Oden.
If Portland don't extend the QO, he becomes unrestricted, so Danny could offer him a 2 year contract similar to what Davis is making (3 mil/year).
If the Celtics could get Oden, I think he'd have a chance of playing without the huge pressure he's bearing in Portland. There he's the second coming of Sam Bowie, and in Boston he could live up to lower expectations, and maybe reach most of his potential.