While I love this idea, I think a compromise can be made. Have the shroud for dungeons most definitly, you haven't been there you shouldn't know the layout. As far as the outside world, I have no problems with it, as long as you are a stranger to the area. If you the character are not a complete stranger to the land, you should know the general layout. Sure you can keep the character from fast traveling to cities he/she hasn't been, the same with other places, but if your character is someone who lived in Skyrim or has lived in Tamriel at all than a shroud over the whole land isn't needed nor would fit.
I like this idea.
Oblivions was fine, but I like the idea of what happened in the Shivering Isles, you knew where New Sheoth was, but you couldn't fast travel there. I like a map where you know where all the major cities are, but you can't fast travel there until you've been there.
Because it's not an actual map that your character is carrying, it's a representation of your character's knowledge of the region (or of the parts of the region that you, as that character, have explored).
Actually, it IS a map that your character is carrying, it just doesn't appear in your inventory. Note some of the dialogue in Oblivion - like 'here, I'll mark [location] on your map'