Spoke to someone in planning today:

There will be a May AE, but it will only have 777 slots open, and there will be no backfilling. So unless you're bidding over to the 777, don't expect to move.

There will be another AE in either August or September, once they have solid Fall/Winter flying projections, and they will back fill then as necessary. There will also be a lot more 777 slots.

If you change aircraft on the 2nd (Fall) AE, expect to be in training early 2009.