In eyeballing DFW man's picture of DL's DFW terminal I notice a couple of things:
1) I'm not sure DL could expand their terminal to the south. Isn't their catering or cargo center just to the south. And I believe the cross-airport taxiways are also in the way.
2) It looks like Dfw-man's flight (is that an MD-80) had a long takeoff roll. Most flights departing runway 17R are higher than that upon passing DL (17R is 13,401', and DL's terminal is close to 10,000' down that runway)...just an observation.
Tom in NO (at MSY)
"The criminal ineptitude makes you furious"-Bruce Springsteen, after seeing firsthand the damage from Hurricane Katrina