Pfft, there are several other, much more impressive things out there than what I'm doing. Look for a little bit and you'll find a few instantly. That's the beauty of Minecraft... While that Game of Thrones thing does look incredibly good and the Minecraft constructs themselves are impressively done, it does seem he copied his maps into a 3D rendering program to take those screenshots... Cheating a bit. :P
In the mean time, my map will be a playable adventure that will work with ordinary Minecraft (cosmetic mods to improve atmosphere are optional), and I intend to cram in a lot of detail eventually.