Crossing from Arkane Studios
Crossplayer. I don't know if you guys remember a project from Arkane Studios several years back, called The Crossing. Not only the game had an ambitious setting, but it was paired by an ambitious concept: Merging Singleplayer and Multiplayer into something tentatively called Crossplayer. When you play the game like singleplayer with all the story and narration, the same game would play out as a multiplayer to other gamers and they will take the role of the enemies or allies throughout the gameworld. It sounded way too ambitious to be true, and sadly the project was cancelled due to financial and technological constraints at that time.
The Crossing Trailer 2 (via munkey505)
Now, its a completely different picture. We are in 2013 and always connected and social experiences are interwoven into our games and it is becoming transparent than ever before. Recent games like Watchdog which allows other players to take control of someone else's gameworld through devices ingame without actually being there to help or hinder progress. Then there is Bungie driving the same idea with their own game Destiny, similarly they want us to have a 10 year long journey with our friends in their universe and shape our own destiny through our own actions and exploits.
I never really liked multiplayer compared to singleplayer experiences, but I am extremely excited about this new ambitious direction some of these games are going for.