So you think it will take 5-10 years to implement server-side extensions to add conference rooms, bars, classrooms, shared white boards, etc? Don't you realize that the bowling alley, arcade games, and pool are already a lot more work than this? For example, moderated chat could be done with no modifications whatsoever to the client, it can be done purely on the server-side just like Source engine commands which intercept chat messages and reroute them.
Apples to Oranges. ID had to go from tech demo to delivering 40 hours of game play. They had to develop the game, the game logic, weapons, art assets, etc etc. We're not talking about developing vast amounts of content. We're talking about taking a movie theater already demonstrated on HOME and modifying the server-side chat logic so that chats can be moderated, and so that thousands of people can be in the same room without clutter by sorting them into identical looking rooms of N people each (N=16/64/128/etc) while allowing certain VIPs to exist in all rooms and for videos to play in sync in all rooms.
This won't even require client mods IMHO. The server is responsible for reporting to the client who is present in a particular area. It can easily maintain the illusion of multiple rooms existing in the same physical location simply by aggregating people into mutually independent groups and not sending visibility information to clients of people who are not in your group. IMHO, something like this is a simple modification and probably only a few months of work.
It took me one week to implement something like this on a Jabber server for a customer support application, that allowed multiple customers to be in the same "chat room" but not be able to see or hear each other, whilst customer support reps could span multiple virtual rooms.
