I believe October was the end of NW/DL's link with Continental. And since I fly UA about as often as CO, it didn't do me much good either direction.
I do wonder if Continental's move away from DL/NW opens the door for YX to restore some lost frequencies to EWR, and to return to Houston...probably IAH this time. Flyers in the DL/NW/YX group no longer get credit on those Continental flights.