Oh, and I'm shocked at the disparity between Oblivion's trailer and Skyrim's.
One difference is that Oblivion's trailer actually showed gameplay footage. Because that was an actual trailer meant to show gameplay and this is just a teaser trailer. Kind of like that Fallout 3 video that showed the radio playing I Don't Want to Set the World on Fire and the person in power armor that turned out to be part of the intro movie and such. I've seen lots of companies do this sort of thing before. I guess it's an effective way to gather interest in your game without actually needing to show any of it.
I'm sure we'll see a video showing actual in-game footage in time, but not yet. My guess is we'll get some real information on the gameplay, story and setting and some screenshots before we'll be able to see the actual game in motion. And system requirements usually don't get released until closer to release. And considering that as of yet, we haven't even gotten a look at the in game graphics, I wouldn't dare to speculate as to what they will be.