Graphics really aren't as important as the average gamer thinks. However, they clearly work to market a game and to increase sales(on some level). Still, how does one explain the phenomenon of minecraft(has sold 2 million copies)? At the end of the day, all games will ultimately be judged on the gameplay. Most reviewers fail to properly discuss how gameplay and funfactor coexist within modern games. They always focus on the technical aspects! Still, no matter how ignorant people are, graphics matter a lot less than gameplay does. Gameplay is what sets a good designer apart from a poor one. It takes real genius and ingenuity to come up with fun, in-depth gameplay systems.
If Skyrim's gameplay svcks, well people will remember it as being a bad game, regardless of the graphics. Just sayin.
Edit: Oh, and once you get to the graphical fidelity that Skyrim appears to have, let's just say that I am impressed and desire nothing more from them.
It depends on what the game is trying to achieve. Minecraft is so obvious that I think people don't care about graphics then. It's the same deal with Mario.
If Skyrim has bad graphics it will be dumbed down and will fail. Graphics is important for immersion and to make the world believable.
If Skyrim has bad gameplay it will be dumbed down and will fail. Gameplay is important for the player to have lots of things to do and to interact nicely with the environment.
If Skyrim has bad sound it will be dumbed down and will fail. Sound is important for immersion and enhancing the atmosphere of basically everything in the game.
If Skyrim has bad story/lore it will be dumbed down and will fail. Story/lore gives everything in the game a meaning.
All things matter. I don't think one thing matters more than the other, considering what TES is really trying to achieve today.
Also, having really really great graphics also take lots of genuises and ingenuity for it to get into the game. It's not as easy as to switch an on/off button.