Rumor has it that Konami will be publishing a Guitar Hero arcade game, developed by Raw Thrills. Although still only a rumor, it seems silly that there isn't already a Guitar Hero arcade, and inevitable that they'll make one.
Plus, there's now the "confirmation picture" you see above. This news comes from the IAAPA (International Association of Amusement Parks and Attractions) Expo 2008, set to take place this week in Orlando, Florida. So, it seems this rumor will soon be concretely confirmed, or denied. Probably confirmed.
No word if this machine will be able to handle G4's uber-shred abilities.