Google can update apps independently of the OS. Youtube, Gmail, Maps, Market - are all updated independently of the OS ever since Froyo. They will eventually r

Google can update apps independently of the OS. Youtube, Gmail, Maps, Market - are all updated independently of the OS ever since Froyo. They will eventually replace the stock browser with Chrome, but they're waiting until it's not beta anymore, and until ICS has bigger marketshare, or maybe they'll just make it the default browser starting with Android 5.0.