Definitely more of the Uzumaki Clan... (Maybe Jugo Uzumaki and Karin Uzumaki starting the clan again)
Kakashis and Obitos Susano...
Maybe Obito giving Naruto his Rennegan or Sharingan...
Showing different ways to becoming a Sage and learning Senjutsu, (EX. Like Naruto at Mount Myōboku learning from the Toads, and Kabuto at Ryūchi Cave with the Snakes) Maybe there could be Senjutsu learned from the Ninken, [Kakashis dogs (ect...)]
Naruto somehow becoming the Jinchuriki for all Juubi... (Knowing all the Juubis names was inportant, they just havent revealed the significance yet)
Naruto becoming Hokage, maybe even ending Shippuden and starting a completely new series several years in the future, like they did in the past... Showing him as Hokage, training to learn new Jutsus, or mastering onother nature other than wind, Maybe even create new Jutsus like the Hashirama and Tobirama did.
HONESTLY, !!! IVE BEEN Reading and watching Naruto since 2004, I was still In elementary school, It has become a part of our Lives, IM 22 NOW AND I STILL STAY UP LATE ON TUESDAY NIGHTS JUST TO READ THE MANGA, WHAT IM SAYING IS So I DO NOT WANT TO SEE IT END PERMANENTLY... I CAN HONESTLY SAY THAT WOULD SUCK MORE THAN WHEN DRAGON BALL Z ENDED!!!