OMFG!!!
From the ign article
As for the fighting itself, I experienced all the same over-the-top action we saw back at New York Comic-Con, but I also learned a few amazing new facts. By far the most significant: you’ll actually be able to choose between two completely different sets of controller inputs. If you enjoy Mortal Kombat’s traditional “down-forward-punch” style, you can stick with that, but if you prefer Street Fighter’s quarter-circle-oriented inputs, you can switch over to those instead. To my knowledge (and correct me in the comments if I’m wrong), no fighting has ever gone to these lengths to accommodate player preference.