No clue what's going on by DL2 on Flightaware shows delayed with an estimated departure of 10:05 PM. I wonder if the diversion was due to weather in the NYC area.
Flightaware
http://flightaware.com/live/flight/D...030Z/KBOS/KJFK
DL
http://www.delta.com/flifo/servlet/D...y&request=main