Well, we do know there is going to be a patch before the XP, but the only thing I can't think of that we've learned so far that might be implemented in it rather than waiting for the XP would be the 10 --> 100 HP increase and maybe some of the Diplo changes (i.e. no more "You're trying to win the same way as we are." penalty). Other than that, I think everything else (Religion, Espionage, new civs, new units, new techs, altered tech tree, changes to existing civs' UAs, etc.) will be in the XP itself.