On one hand, it seems a little unsubtle for Apple. A little too strongly branded. Apple usually places their logo on their devices so that it faces away from the device’s owner: Apple wants other people to know you’re using one of their products, not constantly bludgeon you with their brand.
Until now we can’t confirm this, but it is said that iPhone 5S will have a fingerprint sensor underneath the home button. Perhaps this sensor requires a larger “window†to work than the current home button icon could provide?