It looks like AMD is planning on dropping some prices next month in preparation for an action-packed fall.
As the new ATI cards are expected to hit in September, this move could simple be a way to lower inventories and make room for new stock. It could also be a move to grab a bit of NVIDIA's market share while they don't have much of anything new to offer. If the G300 chips don't come until 2010, this will give ATI plenty of time to kick NVIDIA while they are down.
The price cuts that are coming next month will drop the Radeon HD 4890, Radeon HD 4870, and Radeon HD 4850 all $40. New prices for the cards should be $199, $149, and $99 respectively.