FUD Zilla claims sales of ATI's Radeon HD 4870 X2 graphics card have dried up since NVIDIA introduced the GeForce GTX 295. The reason is that in this ultra-expensive market segment, buyers only want the fastest card.
In this market segment it is important that you are the top performer and currently Nvidia is a better performer than ATI and there are no any indication that this will change until R800 comes, probably at some point in Q3 2009.
It took a while for Nvidia to shape up and to get the performance crown back from HD 4870 X2, and since they have it now, they are trying to keep it at any cost. ATI will soon launch HD 4890 in performance market segment, but Nvidia will counter with GTX 275 that should be faster of the two.