To the extent that difficulty has an impact on price, and that is far from certain, it will become less of a factor as the number of mined coins becomes a smaller percentage of total coins.  Plus, my understanding is that most of those who received the first batches of ASICs last summer/fall easily made a return on their investment.  I don't think there is any good evidence that the price rose in November because miners pulled their supply from the market. 

In fact, I think that the first miners that received ASICs that failed to return on the initial investment (or will almost certainly fail to ROI) received them in the past few months - a period where the price has been generally declining (due to external factors, but that's my point).  There's no reason to think that those miners are holding their supply - maybe some are, but others may be selling, reasoning that getting 70% of their investment back is better than risking getting less back if the price continues to decline.  The cost of the equipment is a sunk cost in any event - a rational miner will decide whether to hold or sell their coins for the same reasons as anyone else.