I don't really see Tobi as the Sage of the Six Paths. Sure, he knows alot about his past, history, abilities, actions, decisions, and the birth of the bhijus. Still, he's had who knows how long to run around and find these things out. If Kishi makes that decision, I'd be a little let back. I still think Tobi was Madara's Zetsu cloan/lacky made to pull the strings until Nagato could resurrect him. Madara obviously knew about the Sage, so it would make sense if he told Tobi (since he wanted Tobi to do the work after death anyway). After Nagato betrayed Tobi and put a halt to his origional plan, then he obviously decided to take things into his own hands, since Madara couldn't be resurrected.
Tobi being the Sage of Six Paths? No.
Naruto being a reincarnation of the Sage? Just speculation.
Only Kishi knows who Tobi is, so we'll just have to wait and see.