Firstly, the poster,
Secondly the teaser, I'm not going to link it until the official one comes out, which should be during the weekend I'd imagine, but I will give a brief recap.
It had Liam Neeson giving a repeat of the speech he gave about fear from the first movie, as clips from Batman Begins and the Dark Knight play. Then it alternates between shots of Commissioner Gordon in a hospital bed, cropped images of Bane's face and shots of Gotham disintegrating to make the above skyline bat symbol. Gordon talks to Batman, who is offscreen, about evil though the words are hard to make out, and it then ends with a brief clip of Bane looming over Batman as he strides towards him.
Overall it was atmospheric, and I'm really looking forward to seeing one of better quality.
OH! And those viral videos I posted a while back WERE real! HAHA! Validation!