take a gander at this speculative iMac mockup, commissioned by MacFormat magazine. Obviously the missing tech for this idea is a screen that fades in from totally transparent to a usable opacity ...

Personally, I am not a fan of the on-screen keyboard design, I think Apple could come up with something better than that, but I like the black finish on the back even though they'd probably offer ...

Display circuitry either borders the transparent screen, masked from view with opaque paint, or located in another portion of the device chassis. As with other augmented reality systems ...