Jacqueline Briggs, daughter of Jax
Takashi Takeda, son of Kenshi
Kung Jin, descendant of Kung Lao
Mileena as the big bad (or the herald) could be super cool.
Did we also glimpse a stage fatality on Kotal?
Just to clarify, now that I've slow-mo'd the entire video:
Briggs has pseudo-bionic arms with gun barrels in them (XRAY on Ermac).
Takeda seems to have some kind of whip mechanism in his gauntlets (seen killing FerraTor).
Kung Jin is the bow/arrow guy (fatality on Reptile)
Tons of alts in this video also. (Mileena, Human Scorp & Sub obviously, Hoodless Ermac, and the new folks).
I'm guessing the Skull-masked goon will be the training mode dummy/Meat characters for MKX.