The obvious theory as to what was in Kane's bag is his mask. After last week's Raw, we threw out possible directions they could be going with his character and the idea of him going back to wearing the mask was definitely one of them. Kane is definitely due a push at this point and it seems like they will probably give it to him as he struggles internally wondering whether his "former self" is alive or dead.
Raw is definitely going back to the "shock tv" idea as they try to increase the overall interest in the product. This is evident by Vince McMahon's stage accident, Kane freaking out, and the JBL/John Cena vehicular homicide stunt that took place at the end of last night's Raw. It was catered to kids, of course, as they are the only ones that would believe in that type of ending. For those that have asked, it was pre-taped prior to Raw and they used camera angles to pull off the stunt. They had to announce immediately that Cena was fine because they still have a pay per view match needed to sell tickets and pay per view buys.