We run a B2B site over here, and I've noticed a definite drop in IE use, though admittedly rather less pronounced than, say, the Spongebob site above. Just at the moment for July, my numbers are running:
IE: 77.88%
Firefox: 15.18%
Safari: 5.69%
Chrome: 1.16% (finally broke 1% for us)
Everyone else 1% of course. If I compare it to June, IE was at 79.04%, and June of last year was 90.58%, so a pretty good drop there over time.
Funnily enough, the big mover seems to be Safari, which was less than 4% not so long ago, and esp. considering that our desktop software is windows-only (mind you--mac-head that I am--I have re-engineered the site to be more safari-friendly, so I like to think that's a factor).