The lights are on
Capcom confirmed at a recent press event in Japan that Ada Wong will be a playable character in Resident Evil 6. She'll have a full story and everything, but won't be accessible until players have completed the other three scenarios of Chris, Leon, Jake.
In an interview with Famitsu, Capcom said Ada's story is played solo, and when playing the scenarios for Leon or the other two characters, you may encounters players who are controlling Ada. Ada can also change the functionality of her crossbow to launch projecting bombs.
Capcom also revealed a new mode called Agent Hunt where you take control of a creature and enter other players' games online to defeat them. Creature-controlled players can voice chat with each other and cannot be heard by agent-controller players. If you don't want other players invading your game online, you can simply turn it off.
Check out the videos below featuring Ada Wong's scenario and Agent Hunt mode.