I know that the game room exists, but its mostly console games with some arcade cabs. I was thinking it would be interesting to run a 12-hour PC LAN Party as an event? If overnight, have it at a room at the Hyatt?
Personally, I have only run a few personal LAN parties at home (6-12 people), but I know someone who's very experienced at running larger LAN parties, and I have a friend who has volunteered for some huge LANs with the Texas eSports Association, so I think I have the contacts to make a successful LAN Party.
Expanding San Japan to more gaming stuff might also attract a wider audience, and if "LAN Japan" is successful enough, we could bring in some gaming related guests and companies. The eSports industry is also growing rapidly, and I know League of Legends, DoTA2, and SC2 are pretty popular with the type of crowd that San Japan attracts.
I haven't given this idea serious thought yet, I just think it would be pretty interesting.