Extensions and themes, long complained about as one of Chrome's greatest shortcomings, are slowly making their way into the builds. The most recent themes allowable were simple, worked across all platforms, and point towards the future universality of other goodies. The Google Chromium blog discusses some relevant issues as well as the eventual opening of a gallery of extensions much like Firefox has long had that will allow for user ratings and updates.
While the Chrome folks still haven't nailed Flash video rendering, they appear to be getting there. That this should be such an issue for the owners of YouTube is almost comically bizarre, but issues with the Flash plug-in aren't unique to Google's browser. HTML codec universality can't come fast enough (and we may never get there).
While the competition for the fastest browser will never be definitively won, the rivalry and the developer builds that push the envelope can only be good news for consumers. If Safari is your browser of choice, the Google team is only spurring the Mac developers to make your browser even faster. Likewise Firefox. Opera fans, I don't know what to tell you, but I'm sorry.