Ed Boon stated in recent interviews that the power levels would be balanced out to make people like Superman not overly powerful and to create an overall "fair" playing field. He says the MK has evolved during each gen of console (which is true overall) so it looks like this game won't be exactly like any other MK.
You read my mind about Batman smacking around Subzero and the Joker will be sick in this game (I have no doubt he'll be there).