While there were some performance increases promised, we didn't really see much across the board. Crysis performance actually took a bit of a hit with the HD 3870 X2. We wouldn't be in a huge hurry to upgrade to the latest set of drivers unless there were some fixes in the release notes for you.
The chances are the AMD team are hard at work making sure that come June 16th the HD 4850 performance is up to spec and can outperform the competition. There is no denying that this release from AMD is going to be important.
I have to say I'm looking forward to next month to see what both AMD and NVIDIA have up their sleeves for gamers and enthusiasts alike. Hopefully NVIDIA offer us something a bit more exciting then what the 9800 was, and hopefully AMD can create a new competitive card at a good price point.
We should see a new set of Catalysts come out around the 16th with the launch of the new series of cards from AMD. Till then, have fun gaming.