With regards to co-op, this review says, "This game screams for it." I mean...no. Just completely no. The entire point of the game....ugh. No. I don't even want to have to get into it. It's like saying that this bowl of Honey Nut Cheerios really needs some cilantro and tomato sauce on the side.
The entire point of the game is what? To have fun? Many players are social gamers and prefer to have friends along with them, and they don't really enjoy games that much otherwise.
You look at the Skyrim trailers and see an epic adventure to undertake alone. Others look at the same trailer and see an epic adventure to be experienced with friends. Neither point of view is wrong, although in Skyrim's case the latter is left disappointed because the option doesn't exist. And that is, by the way, the entire point of an "option". Nobody is suggesting that Skyrim should be impossible to play single-player. They are only expressing their interest in having the option to play it cooperatively with friends should the mood strike them.
It's very likely that I won't look twice at most of the races available for play in Skyrim. It's still nice that the option is there to play them.