I predict the price of the MKIII will be exactly the same price at Christmas as it is right now. I will be shocked if the price comes down any within the next 12-18 months. It will probably be more like 24 months. When I bought my MKII in December '08 it was the same price as when it launched and I don't remember seeing widespread price reductions on it until 2011(BUT, I also wasn't pricing or looking to buy another one until last fall).
If you can't afford it at this time, that's fine and there's nothing wrong with that. In fact, way too many people spend money they don't have on things they don't need. BUT, if you're just holding out trying to save a few bucks(being cheap) instead of getting it now and enjoying it for the longest time span possible, well to me, that's a poor decision. I would rather pay the "full price" on day one and get and enjoy something I really wanted, than wait a year(or two or more) and try to save, maybe, a few hundred bucks. In that one to two years, are you really going to miss a few hundred dollars(assuming that buying it doesn't over extend you financially to begin with)?