My guess is the three eyed creature is some form of troll, because I believe there's an image of a troll in the Game Informer article that got mistaken for a werewolf.
Just because there is concept art, whiteboard writing or pictures of something in that video doesn't mean it will be in the game.
That's of course true, I mean, I seem to recall a concept art image for Oblivion showing the designs of one of the arms, and the person in it had a spear, I don't think I need to say more, I also recall that in he concept art, the river ran through Leyawiin, with bridges crossing over it, contrary to how the city was designed in the actual game. It's important to remember that concept art might not always accurately reflect what we'll see in the game, the simple fact is that sometimes, things can change a lot in the transition between concept art and in-game models, and sometimes things shown in the concept art might not even make it into the game at all, the same is also true for the concepts written on the white board, they're concepts that Bethesda is considering putting in the game, not ones that have already been imeplemented. Now, you can speculate all you want based on these things, but taking them as confirmation of anything is unwise.
And judging from that dry erase board they really are working on making stealth better. It seems they are trying to implement a "Undetected" "Caution" "Detected" system which hopefully means no psychic guards. It also appears they are thinking about you auto-looting gold when you open corpses/containers.
The different levels of AI awareness for stealth there sounds pretty similar to Fallout 3 to me, where you had hidden, caution, and detected/danger.
Who is holding a short sword in his right hand and a STAFF in his left hand.
Well, we do already know that dual wielding is in, that image, if it reflects what the actual game is like, might suggest that staves will be one handed items though, which would actually make sense with the system they seem to be implementing for using spells.
I also noted one piece of concept are showing a humanoid figure with some green around it, I couldn't make out whether it was supposed to be glass armor or some sort of creature, though, but it looked kind of like green flames, so I'm leaning towards the latter.