http://www.worthplaying.com/article.php?sid=64519Valve is also unveiling a new Boss infected monster coming in the full version of Left 4 Dead 2. Known as "The Spitter" this is the second new Boss infected from L4D2 revealed thus far (the Charger was revealed at E3). The female Spitter has an area attack that can split up Survivors or flush them out of their hiding spots. At least one more new Boss infected is expected to be revealed before launch.
In addition to the new campaign and boss monster the Comic Con showing of L4D2 also includes the debut of the "Mudmen," the "uncommon common" exclusive to the Swamp Fever campaign, and a few more of the 20-plus new items coming in the full product (cricket bat, AK47, and grenade launcher).