New content includes:

New story cut scene at the start (might be changed later).
New building, the Cathedral.
More humans in the level.
New multi-select function. While in the hand control (H), hold down right click and drag over units you own. You can then click on the map and the units will move. NOTE: the red selection circle wont appear on every unit.

To complete the level, the leader vampire must get into the Cathedral and walk towards the back entrance.