When it was first announced BioShock 2 would have multiplayer, many wondered how it would be handled and if it would take away from the single player development. 1up has posted a bit of information that should clear a few things up.

The multiplayer part of the game is being worked on by Digital Extremes (Dark Sector and PS3 version of BioShock). Also, the multiplayer will act as a prequel to the first game where players are Plasmid test subjects for Sinclair Solutions. You can earn experience points to unlock new weapons, plasmids, and tonics. Anyone that played the first game should be able to recognize the multiplayer arenas since they are redesigned version of the first game’s levels. Finally, according the the press release, progression through the mode will begin to reveal the fall of Rapture.

Sounds like they are doing something creative with the multiplayer. Look for more details to surface during E3.

source: 1up