I had the same thought in mind for JFK-LAX. Saw lots of routes in Jan and early Feb for 599 each way, but of course my travel was at the end of February. So I knew they would be opening the schedule this past Sunday, and was eagerly awaiting the website to update so I could book the tickets.. only to find they were all suddenly 1399 and up.
Very bummed. Will keep watching the fare and hopefully it drops towards December.