I was wondering what A/C if any will DL be getting in the next, oh lets say 10 years? Also, what A/C will they get to replace their 732s? and what is left for DL to expand? Like what cities or countries are left? 
If they make it out of chapter 11 Iād expect to see 73G/738 to replace the 732 and MDs, and 783/788 to replace the 767s.
Delta will be going to a 4 type fleet soon if they can make it out of chapter 11ā¦
And look for the new aircraft to be more in the 787 category than 737ā¦Delta will be concentrating more on international destinations than domesticā¦more profitable!
DL, along w/ AA, are probably anxious for Boeing to to design their replacement series for the 737s. Itās pretty widely expected that once production on the 787 begins, thatās their next main R&D obstacle. Depending on how the composites perform (and maintain their value) w/ the Dreamliner, thereās talk that they might be used (more) in the new line (797?) as well. DL and AA both have enjoyed flying the MD80s for some time, but their fleets arenāt getting any younger. While they appear to be able to hold up for another decade if properly maintained (look how long NW has kept their DC9s 
), there will be a pretty large order to be placed by both airlines by the mid-late 2010s, assuming both (DL in particular) stay afloat that long. 
Believe me, Boeing is well aware of this, as well as the hundreds (or thousands) of 733s, 734s, and even some ānewerā 73Xs that will be retired worldwide around that same time. Theyāll try to get the designs laid out ASAP, in an effort to beat Airbus to the punch in that category. When they DIDNāT take this segment as seriously, they were burned by the success of the A320 seriesālook at UA. I would assume that they still feel that one. 