I personally can't see it being another DLC pack, since I'm pretty sure Volition mentioned on their stream that the memory issues are becoming worse. One thing they mentioned is how a Christmas tree launcher and an elf launcher both got cut because they couldn't fit any more weapons into the game, and a certain aspect of the present-delivery activity was cut (I think they said it was gingerbread tanks firing at you or something) for the same reason. However, I could see it being a second attempt as an expansion pack.
Whatever it may be, it involves a SR2 character, so I'm excited. Maybe it'll finally be the fabled conclusion to Dex's storyline everybody has been wanting? Or since time travel shenanigans happened at the end of SR4, maybe you get to travel back to various familiar scenes in past SR games in order to save Lin and Carlos, which is how you get to encounter all the locked homies such as Vogel.