Wow, this is great! My main reference had been the map here: http://www.uesp.net/wiki/File:TamrielMap.jpg but that's... um... <insert Elder-scrolls themed term for crap/junk/trash here. Sorry>. I mean, "Markarth Side" almost directly south of Solitude? Come on! Thanks for making a much better version, both in terms of accuracy, detail, and just looking nice.
As for constructive criticism or ideas (I hope I don't come across as demanding):
Sorry, that's a lot of ideas. Maybe I should just make my own edits, if you don't mind. But I'd want it to look consistent, so what font and software did you use for this?