My guess is that the announcement of the routes will be "real soon now" since PBI's on the route map now and they seem to like to announce routes 3-4 months in advance (and January's in that time frame now). If you do a little bit of detective work on their site, you come to the conclusion that the PBI routes will be added on 1/20 or 1/21 (they seem to like to start routes on Sundays) since their schedule goes through 1/19/2001 right now.
And John's exactly right about looking at FLL to get an idea of where they'll fly from PBI. MCO, TPA, JAX, and BWI almost certainly. BNA is also likely. I'd bet against STL initially even with TWA stopping service from there, but you never know, and I think MDW is too constrained right now to add flights. I think ISP and MSY are longshots, and that PVD, MHT, RDU, and HOU aren't likely right now since they currently don't fly there nonstop from FLL.