I propose a DLC with some new map types, potentially with a couple map type-specific quests/items/monsters.

1.  Winter/Frozen -I say this every year, but a whole map that's all snow/taiga/tundra.  Maybe we could fight/ride saber-tooth tigers and mammoths.

2.  Hellish - a whole map like the burning lands? Think plane of Oblivion.

3.  Top of the world.  Instead of water all around the map we have clouds, like you're in an impossibly high valley.  Very mountainous obviously.  We could fight/ride griffons and wyverns.  How come fantasy games don't have wyverns anymore?  I haven't seen any since the first Dragon Warrior.

4.  Underground - not sure about this one yet.  But I had to throw that in for the theme.

Suggestions welcome.