Sorry for the bump, but since I've been away on vacation for the month, I didn't get the chance to reply to this topic earlier.
The closest thing to Venom on the trailer is the black goo and Topher Grace. The black Spider-Man is symbiote suit Spidey. The symbiote suit acts like steroids: Although it makes him uber strong, he gets POed quite easily (I guess they decided to show that by making him look like an evil goth). The suit also allowed him to shapeshift to different people, but I don't know if they'll still have that power in the movie....hope so though. Did anyone see him shooting webs out from above his wrist instead of underneath? I'll have to check the trailer again, because I remember thats one of the changes he had with the suit.
His weakness was super-sonic sound, hence the bell thing that Dario sed. If the movie spoiler I read was real, Venom WILL have screen time, but it was a very early unreliable spoiler...