How is it? I mean is it the host is a Dungeon Keeper and the other 1-3 players are people playing in a dungeon he created? or is everyone their own dungeon keeper trying to kill/work with each other?

the MP videos don't show much beyond dungeon building...

The multiplayer is multiple keepers against each other. Imagine the standard game where you go up against multiple keepers. The main difference here being multiplayer is that the maps are not unfair for you, they are fairly equally balanced.

With dungeon keeper 2 multiplayer, you can set ai behavior as well to control how they will act in a fight or how they build their rooms.

With dungeon keeper 1 it's very basic, to even get ai requires a bit of tweaking, but you don't get much control over it.

Thank You, I was kinda hoping it'd have been a live action D&D, but oh well,. thanks!

That would be awesome to have RTS/First person team hybrid, like Natural Selection 2 but in Dungeon Keeper.