Although she's reprising Mary from the Pietà, the secret is not "Pitgirl is a virgin." Having trouble divining the message inside this Monday Night Combat wallpaper? Think bigger picture. Seen via Uber Entertainment.
Hmm... P, H, T, F, and U...
If you make those letters correspond to the number of which letter they are, you get 16, 8, 20, 6, and 21, all of which are non-prime numbers. Since this game contains bacon, which is a meat, we can assume that any meat related content will not be prime rib. Since prime rib contains lots of fat on the side, it isn't considered lean, which means the update will not have something to do with not-leaning, and that means it will have to do with leaning, and when you lean, you have to balance, therefore Monday Night Combat must be getting some kind balance update.
(oh and by the way, there's some hard to see, seemingly random numbers and letters that can only be seen on the high-res version of the picture under where it says PHTFU coalition, further clues?)