As for future DL
777s as of June 30, 2003:
Delta currently has 8 777s in the fleet
Delta currently has orders for 5 more 777s to be added to the fleet in the next 1-2 years.
Delta currently has options for 20 more 777s in the future
Delta currently has 12 rolling options for 777s in the future
I believe that the options all depend on how fast delta is able to rebound completly.
Look for additions in Delta's fleet to come from the 737-800 family and the CRJ family...in the later future look for additions to Delta's fleet in the 767-300/400, and in the 757 area (this depends on how many more song aircraft are taken from delta)
Hope that answers all your questions.