1.) The fight with Pein and Naruto will not include anyone else. Konan will engage with Tsunade and others. I think Pein will initially fight with multiple Konoha ninja who aren't up to fighting Pein including Tsunade.
Naruto will return, say he has this fight, they will protest but accept it, and him and Pein will fight alone for about 30 issues or so. This will not be the final fight of the series.
2.) The book that Naruto is going to read will contain his name. It will also contain the six ninja that Jiraiya fought against Pein, so Naruto will recognize them (5 now) at the beginning of the fight rather than the end when Jiraiya realized who they were. This will give Naruto a huge advantage that Jiraiya didn't have.
3.) So far Naruto has learned to draw in nature chakra with sage training. However, I don't know his progress without the oil. Also, we have yet to see him incorporate this new training into existing and new jutsu. They will either show that during training or his fight with Pein, but likely a little of both.
4.) Sasuke is powerful, but there has been so much about him recently that I'm exhausted so perhaps I like him less for it though I still respect him. Also we already know a lot about his background, while Naruto's is filled with mystery. I wonder if Sasuke does enough evil deeds if he will himself be lost in the darkness and become evil.
5.) It would be so cool if the Byakugan could evolve like the Sharingan does. Yes, Neji and Hinata can improve the distance and accuracy of the sight, but it doesn't seem to evolve. Maybe Neji will develop something analogous to the MS. I don't know, but I do enjoy Neji as one of my favorite characters. The Rinnegan improves doesn't it? It increases in rings from one to three, please correct me if I'm wrong.
6.) Lastly, Kakashi is gonna have an ace up his sleeve. I think that it's going to be a new MS technique, but I'm not sure. The problem with this theory is he only has one eye (Sharingan eye).
Thanks