The spirit of Uchiha Madara
In this thread I will try to explain how everything could make sense regarding the latest, heavily discussed events of the manga.
Who is the mind behind the Moon Eye plan?
Madara was the one who started the moon eye plan, not Tobi. Why?
Madara knew about the plan, but he couldn't possibly have known Obito.
Madara worked with Zetsu as his loyal sidekick to assist him in his mission to put the world under an infinite illusion. When Madara awakened Rinnegan, he wrote down it's secrets in the Naka shrine. When he shortly after this was dying (unknown reason), at the time when Nagato was just a little kid, he left everything including his eyes to Zetsu so that Zetsu may first of all transplant his Rinnegan to Nagato being the rare and Rinnegan compatible Uchiha/Senju hybrid he was and then watch over him making sure he would use Rinne Tensei on Madara so that they could finish the plan Madara had started.
What was Akatsuki?
To make it short, Akatsuki was basically a movement started by Madara himself and Zetsu. Its goal after Madara's death: To recruit competent assistants, revive Madara, gather the tailed beasts and make Madara the juubi jinchuuriki so that he would be powerful enough to cast his genjutsu on the moon, casting its reflection on the world.
So where does Tobi come in?
Zetsu was the only one keeping "the spirit of Madara" (The moon eye project as they called it) alive - until he met Obito that is. He got to the dying, buried Obito, Zetsu being one with the earth itself. Anyways, Zetsu saved Obito and the two got to know each other. What would Zetsu do to contribute to Madara's plan at this time? Recruiting members to the movement - or Akatsuki as it would officially be called.
Obito was a young Uchiha boy, easy to convince and carrying a lot of potential. How wasn't meeting Obito a great opportunity for Zetsu? Zetsu knew everything about Madara. As what you could almost call an artifical son to Madara, Zetsu knew all of his secrets and his powers - the powers that would eventually be passed on to Obito - the successor to Madara, completing Madara's final mission
Kishimoto said in an interview that the relation between Madara and Tobi would be revealed, if I remember right. This relationship contrary to what it could very well be suggesting (That Madara knew Tobi) might just mean that Obito took on the role as the successor of Madara.
Thanks for reading