That said, it's not just auto-update that makes Chrome more attractive. The omnibox, polarizing though it may be, sets Chrome apart from every other browser as far as U[I|X] goes. Oddly enough, that one feature alone is enough to make it my default browser. Were FF as fast as Chrome, I'd still use the latter because I just like using it more. Chrome's sandboxing, V8, and other intelligent features are just icing on the cake.
This, ultimately, confuses me more than anything about the other browser vendors' reaction to Chrome. They've copied or are copying just about everything about it: short release cycles, better JS engines, sandboxing... but not the one definitive UI feature that has made it so attractive to so many people. This surprises me. I would have though Apple, at least, with its commitment to minimalistic UIs, would have been quick to hop on that train, but no dice.