Based on the livestream it was clear that a few characters have some great combos and defense-offense capabilities. Jade, Sindel and NoobS stood out.
While I agree that all the characters are freaking awesome, especially Kabal, they seemed more balanced (for example, Kabal's dash was easily blockable, whereas NoobS could disable his opponent from a distance and follow it with a distance throw without the risk of getting harmed). Scorpion looked OK, maybe because he was the guy everyone had experience with (seriously, they shouldn't have used him for half the fights...).
Sonya looked really good too, quick attacks that can cover a lot of distance. The stance changing they hinted about will be tough to control but probably be pretty rewarding in high-level play.
Striker's X-Ray looked like one of the strongest in the game (it did like 38% damage alone). His pistol combos nicely into his moves but I find his other combos lacking. Gonna have to check him out, he actually looks pretty viable.
Shang-Tsung looked pretty slow and his soul-from-ground special didn't cover enough ground to be able to consistently be used in midfield combos, although the EX-version apparently does.