It seems like all the cool stuff that was intended for MKDA but never made it will appear in MKD.
Stage fatalities, interactive arenas, multiple fatalities, in-game wall tricks (like Kung fu movies), breakable walls, are all making it in MKD! (if you check out the stuff in the kontents page, the ones with the stick figures, etc) you can see all the stuff that'd whet your appetite for the game but are just not in MKDA!
Nice to know that this time, they will be in the MK game!

P.S. Gosh I hope the sea dragon fatality makes it in the game!