Would be surprised if we don't get a character reveal in time for Halloween. My bet would be the guest reveal. My money would be on Jason Vorhees but if it is an original MKX character I'm hoping we get to see Baraka and Sheeva's baby all grown up.
If its Jason Voorhees or Mike Myers as the DLC i just wont even bother to get them. The only acceptable Outside the MK Universe character would be The Predator IMO