Yeah but in its current incarnation, it doesn't give you an escape route at all unless the app specifically returns control when it receives that button, i.e. it binds to and looks for that button. So right now there seems to be no good reason the kernel is holding onto it.

Not being able to push the "play/pause" front panel button kind of defeats the purpose of having userland apps which can overlay on the screen. I don't think this was left in intentionally.