I haven't really viewed this trailer since I first got Skyrim, but I was on the Steam Store Page for the game and it was playing. I looked at it and just after 1 minute 30 seconds, you see the Dragonborn assassinating some random patron at The Bannered Mare.
Video
I find this kind of funny since I don't remember ever having to do that for any quests, which means they are deciding to randomly murder a patron at the inn.
There also seems to be a female elf of some sort staring right at the assassination taking place. However, she doesn't look familiar from the actual game itself.