An Early Peek At AMD's Radeon HD 4870 X2
Dr. Damage writes "AMD has quite a hit in the Radeon HD 4000 series. Coming up next is a product code-named R700, a high-end graphics card based on two 4870s paired together. TechReport has a preliminary look at how the card — to be called the Radeon HD 4870 X2 — performs. Nvidia could have one heck of a fight on its hands."
You have a misconception about what temperatures should be. They should be whatever the manufacturer rates the part at. Not all parts have problems with high temperatures. My 8800 runs at about 90C and has done so for a long time, still works great.
Have some faith in the companies to test this. They have it run hot because it can run hot without ill effects.