Drop everything and watch Oculus Rift CEO Brendan Iribe describing to TechCrunch Disrupt his intent to build a billion user MMO:
Second Life during its heyday had this as its mission statement:
“To connect everyone to an online world that improves the human condition.”
Now, says Iribe (using MMO interchangeably with "the Metaverse"): "This is going to be the largest MMO ever made... a billion person virtual world MMO is going to require a bigger network than exists today." A billion isn't everyone, but it's close enough (for now). And as the TechCrunch interviewer notes, this is a shift from how Oculus Rift was originally pitched, as a gaming platform.
And about 12 minutes in, Iribe talks about a multiplayer avatar-to-avatar platform developed for Oculus Rift by Valve: