I like this - the right side makes me think of the US <-> Russia land-bridge-made-of-ice maps. Having a more solid/permanent "land bridge" is a cool idea, especially if ocean travel isn't really feasible/possible for some reason. Blue for water might help visualize land masses vs. water ^-^
I also wonder what the poles/pole-areas would look like on a globe - just from this map I'm thinking they'd be kind of "pinched" looking. You could try loading a non-PSD file through the free G.Projector program (available on the forum somewhere) to see what the poles would look like. The program can show the map in different projections, and can even apply graticule lines at different degrees.
Good luck!

- kes