There's also the speaker and mic, the power and volume buttons, and the toggle switch (mute/rotate/etc). If they could use identical transducers that perform w

There's also the speaker and mic, the power and volume buttons, and the toggle switch (mute/rotate/etc). 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.