Verizon's network is already prepared to handle the iPhone. Last year they welcomed jail-broken iPhones on their network. T-Mobile and Sprint would have to upgrade their networks and trust me, Sprint would need to big time and eliminate all of their dead zones.
The design in the drawings isn't practical. Undoing an extra flap in the back? That's a pain in the ass.
If they had a magnifying glass-type material around the edges of the lid, it would collect and refract the light into the screen.