I recently posted up our HD 7970 crossfire results. AMD released their 8.921.2 RC11 driver update the same day as our last post. Here are updated graphs showing the crossfire performance with the new drivers. I still experienced flashing and artifacts when in game water was in view and our test bench would have odd lockups when left sitting idle for a while. The performance increases with the new drivers are impressive, I hope they work out the rest of the bugs. Two HD 7970's is the best performance you can get currently (short of adding even more cards, lol) but without the driver support its going to be a tough sell.
As you can see the new drivers made a big difference in our numbers in 3Dmark. But Dirt 2 and Metro 2033 numbers are still hurting. In dirt 2 for example we saw less performance from crossfire than we did from ether of the single cards! Also we have added Crysis 2 and BF3 to future video card benchmarks, but not until after we did this set of benchmarks. I will work on filling in some of the performance testing on those two games on these cards and other past cards.