Blizzard Entertainment and Valve Software are joining forces toward the ideal of a unified online space between all consoles.
Gabe Newell of Valve has told Develop magazine that it would be "ideal to have a unified online community regardless of the platform that gamers are playing on", and Frank Pearce of Blizzard Entertainment has separately told Develop magazine that the industry needs to "figure out how to make the internet better instead of figuring out how to keep customers off the internet".
With the success of Portal 2 (and the upcoming Counter-Strike: Global Offensive) on having cross-platform play between the PC and PS3, Valve has already expressed its disappointment over Microsoft's online restrictions while praising Sony for the PS3's open platform. Sony also plans on having cross-platform play with PC for CCP Games' upcoming Dust 514.
At the same time, Pierce accepts that cross-platform play may not be best for every game:
If you have a gaming experience on the PC that you want people to enjoy on the console you may have to adapt components of that experience to different platforms. So maybe that isn’t a level playing-field. Maybe some games are best as a shared community rather than a shared gameplay experience. It really is completely dependent on the game itself.