Mortal Kombat's reputation for keeping things secret isn't standing up very well to the internet age. I'm sure there's still plenty of unlock and discover in the retail build of Mortal Kombat later in April but the game is springing several leaks.
Obviously we've already seen the roster list in text form but a screenshot from Neogaf reveals every fighter and their positions on select screen. If you're still not satisfied by reading or even leaked DLC characters here's the screenshot for your eyeballs: