On first glance, the new drivers appear to have made the game slightly smoother for me. I'd guess I'm getting a few fps more on average now, and I'd say it's more that my lows aren't as low, as opposed to the highs being higher. I could very well be crazy though (I blame it on Doom).
For what it's worth, I got 29.2 fps on timedemo 1 with the beta driver (I didn't run the bench with the old driver... sorry). I'm running in 1280x1024 high quality.
Athlon 64 3200+
128MB Radeon 9800 Pro
Back to Doom.