A "next-gen" Mortal Kombat was announced back in September of 2006 but hasn't been heard from since. That looks like it is about to change. Noob.com, a website registered to Ed Boon and Midway Games, has recently updated with a countdown clock. Ed Boon is the creative director of the Mortal Kombat team.
The countdown ends in just under 20 days and promises answers when it runs out. It just so happens that Midway's Gamers Day event is April 17, roughly 20 days from now.