This is amazing - I keep wanting to click on things as if I'm looking at a game like Endless Space instead of a map image. I halfway expect little pop-ups to appear under my cursor when it hovers over every planet and moon. That's a great feature of a fantasy map, in my opinion - not just the presence of information, but the suggestion of more underlying information.
I really enjoy the way you've re-imagined the Game of Thrones world, too. It makes a lot of internal sense, and it builds features of the original works into its own logic.
One critical point: With such a high resolution, what is your preferred method for displaying the map? It almost needs a computer-game-like zoomable view, or a large poster printout.
Finally, you get some rep from me!