A new image of the new creature - commonly referred to as "Endermen" - was released recently (enhanced here, for light levels). This image is much more up-close-and-personal than the first, giving us a good look at the new creatures. It would seem that wearing a pumpkin prevents the new mob from seeing you, although this is unconfirmed at present.
Additionally, Notch mentioned a possible name-change for the newly minted mob, "Farlander" being suggested and, apparently, already in heavy use.
"/v/ is petitioning me to change the name from "Endermen" to "Farlanders". How about we just rename the "far lands" to "the end" instead? ;D"
This means Notch likes the name enough to change the name of the Farlands. He is NOT considering a new name.
^^^^^^ This ^^^^^^ Don't do this poll to MAKE Notch change the name into Farlanders while he doesn't want to.
It sounds like a new feature to see injured mobs. As for assuming the zombies and skeletons working for each other now, thats wrong. Notice how the zombie is looking dead on at the skeleton, its obvious the arrows in its back were from the skeleton.
Endermen have green eyes!
Farlanderto Endermanand
Far Landsto The End