I've seen tons of apps that try to solve the "I want to hang out" problem. They all fail because cool people don't use those apps. Psuedo-anonymity can potentially solve this.
Some tried to do anonymous matching, but those had cold-start-network-effect problems. Psuedo-anonymous social networks might be able to back into a solution by attracting early adopters with their "gossip network" use case.
This reminds me of how Facebook backed into essentially being a status, photos, and events platform when it started life as a networked address book.