The versions were delayed previously, but have now been entirely scrapped. In a statement, Warner Brothers said:
After months of development, Warner Bros. Interactive Entertainment has come to the regrettable conclusion that we cannot release Mortal Kombat X for PlayStation 3 and Xbox 360. Please know our teams worked diligently to meet the quality standards set by the current-gen versions of the game. We were not able to get the PS3 and Xbox 360 versions to the quality expected of a Mortal Kombat game and are very sorry for not being able to deliver the products as originally planned.
Honestly, this is probably the best course of action for everyone. No one wants a sub-optimal fighting game and Warner Brothers could really do without another problematic launch. I do feel for those who had been waiting for the game on their systems all this time though.