1. The new spider queen model. Much creepier.
2. The fact there are greater dire spiders, and whisper spiders, or phase spiders, that will spill out of the cave onto the road in greater numbers than previous.
3. See above, but for Juju Zombies at the purple crypts. AND, for the abberations at the demonologists.
4. The new fire minions. Very swanky. And they don't prompt newbies to immediately poop their pants like the old Balor-looking ones.
5. The new Broken One models, including the big scythed champions and big winged champions, and even the little lizard fellows.
6. The various new striations of thoul and hobgoblim.
7. The new fog and demon distribution at Lysagia Hill. Much tougher, and looks better.
8. Citadel newness.