Raiden so far is partially canon. I do hope he has kicked Kotal Kahn's ass into submission, but despite it would be awesome to see Outworld having to use the MKT to defend itself, I highly doubt Raiden would turn into a konqueror. He would most likely kill Kotal Kahn, if we follow his idea.
So I believe Raiden might just pressure Outworld, but I don't think he will invade it as it seems he's doing with Netherrealm.
It would be nice if Erron Black killed Jax, that would justify Jacqui in the roster, but not her dad. Ermac's ending would be nice too, I just wonder what would be if Shang Tsung had Shao Kahn's soul.
Cassie's ending could also be true, no hate against Shujinko, actually I like him, it's just it could fit with Ermac's and Raiden's.