Delta currently claims to offer Wifi on every domestic Mainline Aircraft Flight in the Continental USA.
There are several ETOPS ex-TWA aircraft that don't have it. So accordingly on the following flight... there was no wifi.
Flight: Delta 1843
Departs: 3:55 pm from New York - Kennedy, New York
Arrives: 7:20 pm at Seattle, Washington
Tsk Tsk Delta.
Note that I did ask the Flight Attendant who checked with the pilot and no - there was no Wifi on this particular aircraft. Further it was the usually scheduled equipment. (VERY NICE SEATS if they worked properly).
A Delta crew member deadheading on the flight advised that there are actually 6 different configurations of DL 757s including the 2 configs of NW aircraft, the exTWA group, the conventional DL domestic and the pure Delta ETOPS planes. There is another group but I was unable to ascertain which they are.