Fighter Mortal Kombat vs. DC Universe is an interesting tie-in. On one hand, you've got MK and on the other DC Comics. Interesting! But MK creator Ed Boon has even bigger dreams.
In an interview, Moral Kombat vs. DC Universe senior producer at developer Midway Hans Lo dishes, "Ed has always wanted to do a mash-up — that was one of his dreams. His dream is MK versus Street Fighter, that's obviously the game he wants to make more than anything else in the world. For various reasons that's obviously not going to happen anytime soon!"
MK vs. DCU came about thanks to someone senior in the Midway marketing department knew someone senior in business development at DC, and they "concocted" the game and viola, here we are today. Now, if only Ed Boon and his eyebrows could get Midway and Capcom together, his dream would be totally real.