If the slot machine is any indication, the one major character that isn't there is the Burgess Meredith Penguin. IOW, just a gut feeling but the people that arrange licensing struct deals with most the characters to do the slot, hope Stern (if this is all true) can piggy back along and get the same deal.
http://www.aristocrat-us.com/#!batman/c1pj3
IMO, this would be a huge success for Stern. That is as long as they don't screw it up. It must have a full color display. Unlike so many other themes, this could go anywhere. The band pins and gore themes don't fit in so many places.