Videos and Trailers

"Left 4 Dead 2 Trailer - E3 2009" Video
This is the first teaser revealed for Left 4 Dead 2, it features the new Survivors of the game, some new upgraded Infected and the new Special Infected called The Charger, along with the new 4 Close Combat weapons, the last close combat weapon, the Cricket Bat wasn't revealed until IGN.com's announcement.

The teaser was released on 1st June 2009 as Valve announced Left 4 Dead 2 on their website. 550px

"Left 4 Dead 2 Trailer - E3 2009" Video Transcript
[Music starts to play in the background as Louisiana reveals]

Coach: "Last time I saw my grandmotha', she asked me was I still a prayin' man. I told her: "Yes ma'am." "Well," she says; "Pray harder." "

[Three F/A-18C Hornets planes flying over the city]

Coach: " "  'Cause it ain't workin'!"  "

[Explosions start, the Infected have been alerted and starts to charge the Survivors]

Coach: "Heh, I ain't gonna' die wait'n on salvation. 'Long as we still got guns, we gonna' fight."

[The Infected are being shot, The Charger starts to charge the Survivors and suddenly Coach runs out of pistol ammo]

Coach: "And if we run outa' bullets..."

[Coach picks up a Chainsaw, while Ellis holds a Axe, Nick holds a Frying Pan, and Rochelle holds a Baseball Bat as a horde approaches]

Coach: "Baby, they gonna' wish we hadn't!"

[''The Monsters Without starts to play as the Survivors attack the horde. The new logo, game cover, release date and credits shows'']

Trivia

 * Strangely enough, it is clearly seen that Coach at 0:48 is wielding a pistol, and the pistol runs out of ammo. By normal in-game standards, this is impossible. However, this might just be an error on the developers' part, as in videos pistols do still have unlimited ammo. Although it is still required to reload pistols which is most likely the reasoning this occurred in the video.
 * The sound of the Baseball Bat is taken from another game of Valve, Team Fortress 2.
 * As seen by the banner in the opening scenes of the teaser, the infection seems to have hit during the "Louisiana Fall Festival".
 * The Infected seem to be able to have missing limbs as seen in the trailer, whereas in Left 4 Dead, they die when their limbs are blown off. This could mean that the virus has begun to strengthen its victims to a degree.
 * One can see what appears to be the Army bombing the infected, and that these are breaking through fenced barriers, implying Valve's statement that New Orleans had been until now relatively safe from the infection.
 * If you watch in the beginning, you can see three F/A-18C Hornets flying over. This indicates that the military may make an active appearance for once in some way.
 * The Infected seem to be smarter and more aware of their surroundings as they seem to take notice to the jets and appear to be running from the explosions, but not intelligent enough to understand that their body can't survive jumping a bridge.
 * As seen in the trailer, the game itself is more gore and bloody than the prequel Left 4 Dead. Infected have actually lot of blood coming out of their mouths.