are reporting Valve have revealed an all-new multiplayer mode for Left 4 Dead 2
at an event in San Francisco.
The mode, called "Scavenge", will offer six of its own maps and pits infected against survivors with a time limit. The catch being survivors can add more time to the time limit by collecting gas canisters (of which there are 16 per round) they then use to power generators. Of course, being gas canisters, they're also extremely dangerous, and the infected can set them off at various points per round, also. Matches are broken up into six rounds, with two teams splitting duties throughout (so three as survivors and three as infected). You win by accumulating the best overall survivor score.
Sounds like the guys are really expanding the multiplayer options for the game - it'll be interesting to see how this new mode balances out.