Oh, definitely. I wouldn't think they'd be quite as bad as the airlines, but I could see them changing the pricing without warning the day before announcing the opening of SW:GE. They could also massage prices a little on a quarterly or monthly basis, and again do it without warning.
I can see it working for them if they adjust the (daily) price upwards as tickets sell (for that day) in blocks of 5,000 10,000 etc. Anyone that had already purchased (for that date) is "locked in" at the price they've already paid.