well, there should be more desert and more Mobile- only-stuff FOR MOBILE.
Vampires spawn during Solar Eclipses.I'd like some more sci-fi themed items. I'm having a ton of fun running around with my laser rifle, Destroyer vanity helmet, and followed by an army of The Twins; it just sucks knowing they'll all be pretty obsolete before too long. So I'd like some more robot minions, more laser guns, and preferably some sci-fi looking vanity items. Maybe even some kind of robot pet, too.
I also think it'd be neat to have some vampire enemies, since we've got werewolves. Maybe an item than gives you some sort of vampire powers, like the Moon Charm.
http://forums.terraria.org/index.php?threads/npcs-acting-in-self-defense-guards.4515/Some npc's to actually fight and not walk around getting killed during some sort of event.