Radeon 3870X2 has been seen by the public eye, but ATI forbids any testing of such a product. It waits for the final driver before it releases the numbers.
The story is quite simple. RV670, the chip behind the R680, got out sooner than anyone had expected and the software guys didn’t plan that this would happen.
R680 is made of two RV670 chips and even the card design is finished, but the software guys need at least until January to have the driver ready. This driver is also going to support CrossfireX, so if you want to buy more than two 3870 or 3850, you had better hold your breath until January.