During a "normal" Gen Con year, there is ALWAYS high demand for Call of Cthulhu games and other fan favorites, but the number of Gen Con attendees also leaves considerable room for other gaming systems which are not quite so popular but still have enough fans to fill a table. For example, I love running games of Marvel Super Heroes, DC Heroes and Spirit of 77 games in addition to Call of Cthulhu events and never have problems filling the seats.
Thanks for the updates, Derek! Highly appreciated. :)