Saw this first over on the [H] Forum. Apparently it's not working everywhere, but so far it seems about 50/50 for people trying based on that thread. There's a 25% off visiontek videocards deal through tomorrow, and since some best buys now have 4850's in stock, it will apply. I'd link the [H] thread, but I'm not sure if that's allowed.

http://bestbuy.shoplocal.com/ the flyer is on page 22 for anyone interested, might want to print it off and take a copy with you just in case. Some have been having success getting rain checks even if the cards OOS. I don't think I'm going to try myself, I've got an 8800GT and am going to wait for the 4870. Good luck guys.