Agreed with the supply and demand comments. Clearly Delta is out of tune with the market here. Teach Delta a lesson by saving yourself $900 and costing them $1200. That's the only language they understand. Or take the chance that enough others will do the same over the next week or two and the fares come back down to earth.

What I might do here is a fare lock on United (or AA - do they still do this?) for a week and see where Delta is at then. If it's still an obscene difference, buy the cheaper tickets and treat yourself to E+ or MCE and still come out hundreds of dollars ahead.