The article specifically mentions IE and Opera. While Opera may "claiim" to be the worlds fastest browser, it isn't (when running under OS X).
I have to take issue with the statements the IE engineer made about the problem not lying with IE, but with OS X in general. There may be truth in that, but if that were the case, how could OmniWeb, Mozilla, and especially the alpha staged Chimera/Navigator wipe the floor with IE when it comes to page rendering performance? The truth is somwhere in the middle.
Yes, OS X needs major improvements in it's underlying core 2D graphics. It seems the technology is fine, it's just that Apple hasn't optimized it yet. And yes, Apple NEEDS to offload some of the screen redraw calls to the graphics card (when possible), and freeup the CPU. This will help immensely.
The problem is really obvious on slower Macs with weaker grahics chipsets. For example, my PMG4/800/DP w/1.5GB of RAM is plenty fast in rendering web pages, even in IE. However, my PBG4/500 w/384MB of RAM and a lame ATI Rage128Pro 8MB graphics chipset is much much slower. Couple that with a frequent "SCUD" (spinning cursor of death), and you can sometimes end up frustrated while surfing with it.
Maybe Jaguar will address the issue, but I doubt it. My main hope at this point is that Chimera will become the browser we all want/need, and do it in a relatively short period of time.