Possible identity of Tobi/Madara
Okay, before I have anyone totally undermine my theory, just think about this for a second. I'm not a great storyteller but I know a good story when i hear it. And Kishi knows how to tell a good story. He has left us guessing the identity of this new and incredibly powerful foe. What most of us want to know is just:
Who exactly is under the mask?
People think it might be a clone of zetsu, others believe its Izuna Uchiha or Shisui Uchiha, while even some think its the 10 tailed beast in human form. I'm not saying it can't be any one of these entities. But my strong belief is that it could possibly be Obito.
Now before any of the nay-sayers start trolling. Think about what I said before, this is a great story. The point of having a mystery is that by the end of it, you're face palming yourself saying, "Now why didn't I think of that." or "That makes sense now." Lets look at the story, you have Naruto, the protaganist, and you have Tobi/Madara, though not the main antagonist (the main antagonist would be Sasuke in case you were wondering) but a bad guy none the less. Usually the bad guy has had some relation with a character we've seen before.
For example, Nagato had a relation to Jiraya, Nagato being an antagonist, he fought the protagonist, Naruto. (Please bear with me, i understand it seems like I'm dumbing this down, but it's to try and prove my point.)
So if Tobi/Madara = Obito, who would his relation be with? I wonder? Now I know what you might be thinking, it can't be Kakashi. No way, he has met Tobi/Madara a couple times before and Tobi/Madara hadn't acknowledged Kakashi like that. Well that's because Kishi is trying to make Tobi/Madara evil personified. Which is why he isn't anyone anymore, he has lost everything, he's "No one".
If you recall Obito, he was a little like Naruto in some ways. Always last at everything(I'm talking about before he awakened his sharingan), while Kakashi had to be the best and tried his hardest, a little like Sasuke. Of course they had different reasons for being this way, but their personalities were very similar. But tragic situations occurred it made what Kakashi who he is today. Well its cool that we got a back story for Kakashi and learned a little bit about how he came to be. But there might have been another reason for it. Like to introduce this character, Obito. He left a lot just to be overlooked.
But one more final statement as to why i think this. As i said before, Naruto and Obito are similar in their personalities. The only difference is the situations that occurred (the butterfly affect, if you will). Naruto is and will always be the good guy, the hero who overcomes evil. Well Obito is something along the lines of, what Naruto could have become if occurrences were to prove otherwise. Evil personified.
Well, what do you think?