This is a very sketchy rumor that is based out of the MKO & TRMK forums so take it with a grain of salt but there are some rumors floating around about some possible PS Vita exclusive new characters coming to Mortal Kombat 9 on May 1st. Again, this is all speculation - here is the post:
"Apparently the've been promoting VITA by showing MK the most and the guests that attended spoke of "unrevealed" surprises and extra-characters that have not been seen in the game before. From what I gathered its clear that they are not talking about the DLC! This is mostly from FB comments so I'm trying to get some confirmation on these claims.
Though I can't confirm this information, I've gotten word that selected guests got some special previews of the MK VITA during the event in Bolivia and Chile!
No recordings were allowed but they all talk about at least two new characters that are not part of the already known roster (including the DLC characters).
Reports are pretty vague but they do specify that "he" is not a character from the "PS3 roster".
Most of the selected guests who saw the special preview concede about at least 1 new character while other guests made it sound plural, as in "2 unconfirmed new characters" but that is unclear. At least they all agree about one though...
Nothing is said about them being playable or not. The not-so-detailed reports only confirm that you can "fight" against him. I've yet to read a description about how "he" looks yet.
Props to Queve for the info!"
Original post on MKO, here
Taken from TRMK