The actual convention- NO.
Vegas is the center of the gamblig world (even with other locals getting bigger (ie Macau). It also has the history, the feel, and it is still within most budgets. Many collectors are obsessed with Nevada and Vegas. So my answer is no. But I do think it is conceivable that additional events of various kinds could be held under the umbrella of the CCGTCC (perhaps not sales- but educational or social events, or maybe informal trade sessions). The trick would be to find a group of volunteers willing to take on the task (and what a task it would be).