If you don't quite get why people are freaking out about some cartoon avatars sitting at a table around a slide deck, watch this form Facebook Connect last year. The "Facebook Metaverse" is not competing to be the next Roblox, its competing to be the next human ear and mouth.

"Put all those technologies together, and virtual conversations can become indistinguishable from real ones"

This is not sci-fi. They are actively working on this.