It was interesting to find that AMD hasn't promised any performance improvements, yet we did see some in place. WIC performance is slightly up while UT3 performance under Vista also seems to be up a little. There are also extremely obvious gains under 3DMark Vantage for the HD 4000 series cards.
It seems mainly that the latest driver release was all about bug fixes, though, as the list for fixes in both XP and Vista are actually quite extensive. It also seems clear that AMD have adjusted their focus to the HD 4000 series of cards, which doesn't really come as a surprise.
Really, the only thing we need to look at now is if Crossfire gains are present. But since the driver doesn't mention anything about it, we would be surprised to see any gains apart from Vantage, perhaps.
What we'll do is place the HD 4870 X2 in our testbed along with a pair of HD 4870s in Crossfire. If we see some improvements that are worth mentioning, we will be back with another performance analysis. If we don't, though, we'll no doubt see a new set of drivers next month which will hopefully boost the performance of the newly released HD 4000 series cards.