it just dropped like 10 days ago. but if you must know, Id expect another price drop when penryn launches. which is not a set date, other than Q4. Id guess novemberish.
this is all my opinion. intel has not said when penryn will launch exactly, and they have not announced another price cut on the Q6600.
sometime before the end of the year either way, Im sure you'll start seeing retailers discounting them somewhat.
but really, 10 days after a price drop, if your already waiting for the next price drop just to save 20-30$...