I live in Japan. The way RS is described here is
exactly the way Kurama refers to him Kurama was the only character in Naruto that refers to the sage as old man. It's a pretty obvious hint. Naruto will meet RS and probably inherit the body powers of the older son, or at least the "Will of the Sage". I suspect Madara will retain the "power of the eyes" since Madara technically awakened Rinnegan on his own.
The person near Sasuke is not RS. Sasuke probably got a power upgrade from Hashirama. Notice two things with Sasuke:
One, we never saw what Sasuke and Oro talked about when Sasuke said "I know why you really attacked Konoha". We also never saw the conclusion of what Hashirama said to Sasuke. This is pretty blatant foreshadowing. Sasuke will get new eye hax from MM, and Naruto will receive a new chakra/body mode from the RS himself.
To anyone predicting Naruto will receive Rinnegan from RS, sorry but get real. Notice that the real power of the Sage wasn't the Juubi, but the fact the Rikudo beat the Juubi on his own power and then sealed it within him. RS solo'd the Juubi and created all ninjutsu chakra itself, that puts him leagues above a chump like Madara, sadly.
Madara foreshadowed his own defeat in saying "This world has failed. This world is hell". Obviously Naruto will carry on the Sage's will and defeat Madara through the Power of Love and Friendship, cause that's how all shonen series end