Endermen are probably going to be, unlike other mobs less likely to spawn. I think they'll just be the new herobrine's of the game, they'll just eventually walk around and when you seee them they scare the crap out of you.
What happened, deep in the hidden eras before history began,that could effect the human race so evenly as to give the entire race a deep, lasting fear of pale beings with dark,sunken eyes, razor sharp teeth, and elongated faces?
Enderman... i cant wait till. Creepy night seeking creature that haunts you down. Will give me that alien movie feeling when im goin to take a poop at night.. and about blocks im pretty sure they just shuffle them around the place or have a building script in them ( unlikely ) they migth be able to take wood from your house but not the doors. trapdoors. pistons ex. its a theory not an anwser.