Originally Posted by keeton

In the time from when you booked and when you actually fly next summer, DL will probabbly change the schedules several times and will probably throw in some EQP changes as well. Picking your favorite seats right now will be an effort that ranges from frustrating to futile.

You can pick your seats now, but _my_ advice is to continually check your itinearary from now until your flight. Monthly will probably be good enough until about two months out and then weekly and then daily the last week until the actual flight. If the schedule and/or EQP changes, be prepared to scramble.