mirasol might work in the future.
as your text says:
so far the backside of the mobile is not used today.The technology is still being developed and nowhere close to production.
even worse, some manufacturers even make it with glass, and do not use the space behind the glass (galaxy nexus 4, lg optimus G).
it COULD be used with e-ink !
i look forward to see this yota phone or the onyx mobile beeing published.