Strange, flying from California in November and ours ended up being $339 (so far, it may go down more and Jetblue offers refunds in the form of credit if that happens). This is actually one of the cheaper flights we have had from here.
Although ours Started out at $401, but I setup a price tracker on Yapta, which told me when the price dropped. I called Jetblue and got the difference refunded.
So, it is possible to book now and have it go down, but the refund policy will vary from airline to airline.