It's an excellent idea, I can give it that, but I do not see how this fleshes out into a full game. We're talking about Person A tries to find Person B in a crowd. Person B has stuff to do, Persona A just has to find him.

If you're playing on the same screen (as the article indicated) Person B can't have an interesting interface because it's shared with Person A, and vice versa. Likewise Person B can't be doing anything interesting, because (as indicated in the article) his possible actions are easily investigated by Person A.

Don't get me wrong, I'm all for new concepts in gaming. I play far too many games right now... I just don't see how this extends beyond a Mario Party / Wario Ware style mini-game.