Isn't it obvious? I'm sure it is linked with the last request Obito had on the last chapter. He surely wants to transmet his eye to Sasuke, so then he will have 2 rinnegan. It's foreshadowed by the fact Sasuke appeared with only one eye with the rinnegan.
As I said last week, and as Lady GT said just now, Sasuke has a left Rinnegan. Obito too. So to me it's obvious Sasuke will never have Obito's eye.
In the raw, MADARA is talking about his other eye. It's obvious he wants Obito's eye from the start.
About Sasuke, I think it could be possible that he might never have another Rinnegan. I think it's possible Kishimoto wants him to keep his Sharingan with his mangekyou and everything else.
Edited by Otaru, 21 April 2014 - 12:46 PM.