These are viral video commercials giving a kind of sneak peek into 4th edition. I found them pretty funny since I've played 2nd and 3rd edition in the past. <3 the gnome!
Tiefling & Gnome
D&D 4th Edition: Tiefling & the Gnome (http://www.youtube.com/watch?v=4UqFPujRZWo#)
Demogorgon and Gnome
Demogorgon and the Gnome (http://www.youtube.com/watch?v=5KqjOGdOMtA#)
Red Dragon
A 4th Edition Interview with a Red Dragon (and his cronies) (http://www.youtube.com/watch?v=Azcn84IIDVg#)
Mind Flayer
THE MINDFLAYER INTERVIEW! (http://www.youtube.com/watch?v=17fCLP30E84#)
Beholder
D&D 4th Edition: Beholder (http://www.youtube.com/watch?v=72LQ6W2W_TU#)
... and this one was just funny
Red Box Ninjas
D&D Insider Presents: Red Box Ninjas (http://www.youtube.com/watch?v=C2aV_pIS4rY#ws)