in 2001 it was very slow... but very nice for us guests (just be aware of higher refurbishment possibilities of some attractions and shorter park hours.)
and it was a little chilly (unseasonably) even by Florida standards (overnights in the 40's, day's in the high 60's - low 70's if lucky)...
so check before you go and pack accordingly
you may be a little early, but as it got closer to the Superbowl, the ESPN restaurant at the Boardwalk had events with player appearances (former and current NFL)....