I personally would trade him to the Bobcats for Diaw and Diop.
Diaw contract expires in two years though while Arenas has 5 years
Diaw has two years (9m, 9m) and Diop has three (6.5m, 7m, 7.3m)
Arenas has four years (17m, 19m, 20m, 22m)
So yeah Bobcats will pick up a lot more money - but he is Gilbert Arenas afterall. He was bad last year but still put up 20 and 7, and he is a big name. If MJ is looking to make a splash and attract some attendance he might bite.
Also consider that Larry Brown took Iverson to the Finals so he might know something about how to use Arenas.
In contrast, Diaw is massively overpaid as a backup quality player, and Diop is completely money thrown into the drain.
I think it's a good trade for both team.