Perhaps, the best strategic move for DAL, in that case would be to acquire AS and kill the codeshare competition. Granted, it would provoke a response from AA, but they really aren't in a current position to be much of a threat with the LCC merger on their plate.
Considering the amount of cash currently held by AS, I'm sure the green eyeshade guys at DAL could figure out how to buy us with our own money.
I'll grant you we're the codeshare *****s of the industry.