Neat!

It might be useful to be able to configure the map viewing angle at the top and bottom of the frame, perhaps even the degree of curvature between them.

I say this because I wonder if a shallower gradient (slightly more top-down at the bottom and slightly more angled at the top) would be more understandable and familiar while providing almost as much information. Not as cool-looking, but potentially more useful as a real navigation aid.