It appears US Airways is adding some Pittsburgh-Florida capacity for the winter.
Starting December 14, US adds a third daily PIT-FLL frequency. The third FLL-PIT, however, doesn't begin until December 21. Initially starting with one A319, one A321, and one 737-400.
The route becomes three 737-400's on January 7.
Also, starting December 21, US Airways is adding a second PIT-RSW frequency. Both flights will be with A319's.
As previously mentioned on this forum, daily PIT-MIA resumes from January 6 with a 737-300.
It appears the additional frequencies are only for late December and January. They don't appear in the schedules starting in February.