Since I've got nothing else to do while listening to busy signals, I suppose I'll just keep posting here.
If the statement on the Galactic Starcruiser website is accurate and cruise availability is updated in real time, it doesn't look like cruises are filling at any sort of noticeable pace. I don't think that a single date that showed as "available" when I logged on this morning is showing as "unavailable" now. So perhaps this is a problem of having 2000 people trying to get in on the 2 dedicated lines (or whatever insufficient number) for booking.