They should add any maps from 2 or 3. I would say 1's, but they're kind of small. I wont be buying the next map pack. I'm actually going to delete this one off my HD so I can get better maps more often.
Sadly, this map pack is atrocious, and the only good default maps are Haven, Ragnarok, Adrift and Abandon. In terms of maps, this game is really becoming like Reach. They also ought to consider allowing forge maps in matchmaking, especially remakes of old classics.