Yawn
Big Baby has had a great year, who are we getting for him that is gonna play bigger in bigger spots then Davis?
...Bitter Powe fan?
OUCH! Even I haven't went there! 
More Banners, if the deal can't be done without giving up JO, as far as I'm concerned we're losing a true center and a power forward who can center in spot minutes. Diaw won't offset that, and he's not even taller nor that much a better rebounder than BBD (at least not this year). Giving up the 1st round pick just to get Henderson basically means we're rebuilding, and is he really the answer next to Rondo?
There is a money match-up issue in trading for Diaw, so JO pretty much would need to be in the deal, not that anyone really wants him or his contract, most likely.
Diaw can replace BBD in the backup PF spot, and with his Odomesque skills, would be a great asset. At 27, just entering his prime, too. His contract expires this year, so a choice can be made about extending or resigning.
Henderson is showing his NBA material, which means he's worth a 1st. Doubtful that Charlotte lets him go, but trading away a pick (instead of FOR picks) indicates win-now, not rebuild, at least in most cases. I doubt anyone is sure that Henderson is the answer at the 2, but his dad sure was (1984 title).
I think Diaw and Henderson are probably each more well-rounded players, with talent, have careers ahead of them still, wouldn't make us worse in the short run (better, IMO), are healthy and available to play (unlike JO), and just might be around through a transition to the next version of the C's as contenders.
So...we seem to differ on JO having value. I don't trust him to even be available to play, and if he is, not to be available for more than 15 minutes or so. I like his defense like everyone else, but have little faith in his availability.