If you're looking at the 4850, wait a couple of weeks until the DD5 version comes out. As for the heating issue, an after market VGA cooling system can be added. At the price point the 4850 and the 4870 are coming out at and from the preliminary benchmarks of the 4850 DDR3 512 meg card, ATI has a winner on their hands.
ack-ack
Unfortunately, I can't wait. I have to buy the parts before they stop selling Win XP Pro at the end of this month. I really don't want to have to fight with Vista. Besides, I generally buy one or two levels below max, so that would be the 4850 instead of the 4870
