This is one of those "is it better to wait" questions. The answer is generally yes, it is always better to wait. New stuff comes out, seasons change, prices drop. But at some point, you will have to stop waiting.
As far as economic reasons why prices might be more or less after Christmas, we're talking about foretelling the future.
If people buy a lot of CPUs, there might actually be less product available to purchase, so prices will be higher. If people do not buy a lot of CPU's, such as in a recession (sound familiar?) then there COULD be a lot of extra product on the market, but just as easily manufacturers might curtail supply if they see weak demand.
So, while we don't really know what will happen, hardware value does always depreciate, so it is always better to wait, as long as you can stand to wait.