I suspect Howard will wait quite a bit before making up his mind on what to do. I think Chris Paul will re-sign, so he might do that quickly, but he'll probably test the waters a bit (not that players didn't test the waters before free agency started). Josh Smith might be a big prize for some teams as well.
Other teams, of course, seem to want to be in the Andrew Wiggins sweepstakes instead (and, if not him, the rest of the 2014 draft is apparently pretty good). Both the Sixer and Celtic firesales will be intriguing (Sixers specifically for next year, the Celtics got a ton of picks for quite awhile). Obviously, Celtics fans will be sad to see Pierce go, but it's clearly time. Likewise, I love Jrue Holiday, but I don't think the Sixers were going to win with him so I'm cautiously optimistic about that trade.