Removing the Home Button?

John Gruber states:

We’ll see, I guess. How in the world would you get home on an iPhone using a five-finger pinch holding it one hand? The iPad seems like a “maybe”, but I find it really hard to imagine a Home-button-less iPhone.

I do find it hard to believe that they would remove the button and make people learn multitouch gestures to get around the iPhone. I find it easy, however, to believe that they would remove the physical button. I could easily imagine a rounded white-stroked square printed underneath touch-sensitive glass. I would prefer the actual button, but I’ll bet that the mechanism takes up space that could be used to optimize the battery life a bit, or something along those lines. It also makes for a cleaner device design-wise, though perhaps less usable (and the question of whether a touch-sensitive home button would work in sleep mode remains open).