No, Marvel won't end up with Superman in 2013. The claim that the rights revert to the families in 2013 comes from their lawyer and it's by no means a certainty that he's correct in that. Even if he is correct, it would only be the rights to the material in Action Comics #1. DC would still own the rights of those elements of the Superman universe introduced in later comics. Plus there are added levels of complication in that DC can still claim that Superman is one of their trademarks. Basically the families may end up in a position where they can negotiate license fees from Warners and DC for the use of Superman, but the chance that they'll be able to take the Superman rights and sell them to another publisher or studio are slim to none.
