My FPS dropped as well on my dual 5870s, but, it's actually much smoother at lower FPS post patch. If I turned off Fraps, I'd never know I was running in the 30s at times were before I would have.
I don't mind a lower FPS count as long as it doesn't degrade performance. Though, I admit I'd prefer seeing 60 all the time with 2 5870s. (Silly, I know.) As long as it feels smooth I'm fine with it.
I've noticed an fps drop in some areas with my 5850 that I didn't notice before, The Strip for instance is about 10 - 15 fps lower, a few indoor areas also see strange drops when looking at a seemingly solid wall. I'm also noticing more hitching when traveling than I used to, but I need to look through the ini to make sure nothing is out of whack.
Overall it's smooth though, I'm pretty satisfied with performance this patch on my ATI card.
@Wolfpup: That isn't silly, if I spent $800 on two 5870s i'd want to see 60 all the time too