Google has released their own web browser called
Chrome (more info here
in comic form). I'm trying it out now. While there are still a few rough spots to smooth over (that's what beta tester
feedback is for, after all), the interface is innovative, and the WebKit rendering engine and v8 JavaScript engine make it blazingly fast. I'm unlikely to switch from Firefox as Chrome lacks that level of customizability (there are some extensions I wouldn't want to do without). Still, I'll be keeping this copy installed and watching its development.
I hope the Firefox developers will be inspired to make better optimizations based on this, or even to start using WebKit and/or v8 whole-sale. They're open source, after all.