Jim....many manufacturers are (fortunately) too busy making product to attend all the shows, RMAF included. Zu is out with new speakers, and are probably up to their eyeballs building them to ship to dealers and reviewers. Omega and Redwine are also in the same boat, building product and satisfying customers. It would be great seeing them, and experiencing all the goodies, but it's completely understandable why they're not attending.
Bryan....RMAF's rates are very reasonable, so I don't think it's the actual cost deterring anybody. But being away from "the shop" can be very costly, in terms of orders, fulfillment, and work time lost.