Yeah Eka Steinberg has VST System Link, which allows you to link up different computers running Nuendo or Cubase within your LAN (Local Area Network) connected to a cable which synchronizes each computer with great accuracy and allows different computers to assume various functions. For example computer A could run all the midi sequencing, Computer B could be for recording all the audio tracks or whatever. But that's within one room not very far apart.
But what Wu was talking about were two, three or however many users could log on from different networks sharing the same program working on it simultaneously, I heard something about that kind of thing being done in various big studios, but I believe they're custom written programs that they have setup. I don't know if anything commericial exists yet, but it is out there. I don't remember what studio does this kind of thing I'll look it up and post it here, but they do it from LA to New York and like London or some other far off place.