Screw that, i'm hoping desperately for the Purple Ninja. Mr. Lightning/Water-Kinesis Ball/Super-Roundhouse (that's a lot of forward slashes) is my favorite from UMK3 and the final part of my username to complete my MK triumvirate (The "rai" in my username was supposed to be "rain").
I'm now uber-hyped for MK9 now because of what Ed Boon tweeted in the above post, and I will spare no cost to make sure Rain is in my game.
I don't know why so many people are fans of C/Khameleon. Personally, I don't think they belong in anymore MK games, since they were gimmicks and more self-aware references to pallete swapping than real characters... but I guess to each their own.
Easy, they have potential.
They are members of Reptile's lost race, that could make for a good plot twist in which Reptile leaves Kahn's side.
They could (potentially) combine the ninja's powers, ice spears and electrified acid.