Chrome has some developer tools, but I haven't really tried them out too much. I haven't found the browser to take less RAM than IE 8, and the Javascript doesn't seem faster than IE 8's either (I tried out meebo.com, and it was about the same speed).
One caveat I have is that there is no Favorites panel in the browser. I know they say that their Omnibox is supposed to replace that, but I have to write a whole word of a favorite because it pops up, and I find it much easier to just click a link on my Favorites panel.
Another thing is note that IE 8 has the same "process-isolation" design - it runs each tab in its own process.