I just remembered that Kyuubi mentioned Madara when Sasuke "went" into naruto's conscience thus meeting nine-tails.

Looks like there is a very interesting story between Madara and Kyuubi.

As for Tobi -> it seems to me that he simply is Uchiha Madara and I don't really know why would you want him to be someone else, the fact that he should be dead for quite some time now is not really a problem for Kishi :P