Techland, the folks behind Dead Island, Call of Juarez and others, have just announced their next title, a co-op first-person slasher called Hellraid. This game is coming to PC, Xbox 360 and PS3 later this year.
They call this two games in one. There's a story campaign for single-player play, and then a co-op, four-player multiplayer side that has the group fighting hell monsters and each other.
Hellraid combines bits from hack & slash games, RPGs, shooters, and other online multiplayer games. Its Game Master system randomly places loot and enemies for online challenges to keep things fresh. You'll want to check out the newly launched official website for Hellraid for details.