If you look in the corner of the picture Mojang released of the endermen, you will realize one is carrying a grass block.
Are Endermen going to pick up blocks and move them, or are they going carry around a certain block upon spawn and then place it.
They could also spawn with it and when you kill them whatever block they are holding will drop.
Common consensus is that Endermen will only be able to move around natural blocks...meaning nothing that you have placed. Nobody can say for sure, however.
Endermen only move one block at a time. A creeper can blow the whole side off your house. How is the Enderman such a problem? If you don't like it don't play.
Are Endermen going to pick up blocks and move them, or are they going carry around a certain block upon spawn and then place it.
They could also spawn with it and when you kill them whatever block they are holding will drop.