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.
they (the arrows) will probabaly disappaer after awhile
Secretly living in their own ways and mining for diamond such as you...Explains all the large open cave areas...
All in All I just hope they arent the magical NPC village its been spoke of...
to keep them from moving his house blocks. but they only move generated blocks so its not too bad
They are really really creepy looking, that is why. The block taking thing is not really a problem because I do a walk around my fortress every day plus the walls are four blocks thick.
Stop being so superstitious and afraid Slenderman, to those who are. Obviously if it's just a choice between which one sounds cooler then there's nothing wrong but there are people who pick Farlanders because they are scared of Slenderman.
In all seriousness, he should find a whole new name for them. Neither are that great.