Am I the only person who uses the physical home button to feel for which way is up when pulling the phone out their pocket? I'm going to look like an idiot 50% of the time i pull my phone out once that button goes virtual.
Ironically, there's only a concept of "up" because of the very same home button. If you remove the home button then there is no up and down, since the virtual home button would always rotate to the bottom per gravity.
If they could use identical transducers that perform well as both speaker and mic, then I'm sure the remaining buttons could be made virtual as well (full touch-sensitive sidebars maybe?), although personally I like having certain buttons implemented as physical devices.