Teehan's addition of a flat inner shadow was a useful, but misapplied, technique. The shift key should only stay depressed in the caps-lock state, not the uppercase state. The logic behind this continued depression is made with reference to the "lock" in "caps-lock." Furthermore, it is not enough to add an inner shadow if it is so subtle that the key does not appear to be depressed. Overt depth cues and lighting make the key states obvious.

Almost every proposal offered by the community suffered from the perennial problem of accepting the premise–they ceded to Apple's artificial minimalist constraints in their redesigns, thus handicapping the improvements they offered. What is clear is that designing sufficiently differentiated states is ultimately a matter of whether we make that our priority and in doing so improve our interfaces for users.

Today's Landscape

With the release of iOS 9, there have been a variety of changes to the software keyboard. Unfortunately, none of them have addressed the fundamental problems of its visual design, as much as pundits might claim otherwise.