Honestly I didn't think about Orochimaru, but I don't remember if he has SM.
Well he must have some level of understanding of senjutsu since he was able to create seals with just a bite on the necks of people that are capable of drawing in natural energy.
Hatching is a very common shading teqhnique, it could be just that. Orochimaru's eyes however, obviously resembles a snake. I'm just saying if this is Kishi's way of making Tsunade similar to Katsuyu, he should've done it more visible. Tsunade's eyes are nut brown, which is considered a dark colour(but not entirely black). On covers her eyes are not designed like that, so I don't think it's more than a shade.
Of course, I myself already refuted that possibility with my initial post. However, it does not detract away from the reality of Orochimaru's eyes having the peculiar sage-like markings and pupils of a snake when he was but a child.
The 2nd paragraph, Jiraiya had SM, but didn't complete it. Naruto did.
Both of them were offered a formidable opponent to assess the fruits of their labour on. Already Sakura would likely not experience such an opportunity because regardless of whether she is battling or not her teammates are going to be assuming the brunt of the group's offensive. Still, this is a much more significant conflict that Sakura could display the SSM in than using it on the likes of Juugo, Karin, or Suigetsu in the following arc. The only conceivable methods that could equally compliment a Sage Mode would be if she were to go up against Orochimaru or Sasuke but how long do you honestly believe she would last against the likes of those two? It wouldn't matter as Naruto and the rest of the Konoha 11 would inevitably group up to attack either Taka or Ororchimaru in her defence.
A similar scenario wouldn't hurt and I would like Tsunade to be the introduction of SSM(or Hashi if that is what he has) Sakura needs a jutsu of her own, that I can agree with. I agree with both, but these two contradict eachother DX I guess you can't have both, but then I would be fine with it either way.
I was always under the impression that since Tsunade's transformation ability required a perpetual concentration of chakra to flow throughout her body that Sage Mode would be unattainable for her. It would impede her ability to gather the appropriate sage chakra to enter a perfected SM and as a result she created an imperfect variant or alternative in Byakugou. Well, that's just another theory.
I don't think Sakura will continue her healing duties unless someone important(Kakashi *coughcough*) gets mortally wounded. She just healed the entire alliance, all the fodder ninjas. Another task is up next for her.
If Sakura was intent on fighting then why did she not reenter the fray after healing everyone in the alliance? Could it be that Kishimoto intends for to remain back as a medic on standby for the remainder of the battle? She did state that she was "all ready for healing" at the end of chapter 633. It was emphasised like that would be her primary function now. To act as a healer once again after a single chapter of being combat effective.
What was the purpose of giving her the means to bypass Tsunade's medical rules if she is only to going exploit those benefits for a single attack?
The Kages may take on Madara again, I don't see what else they can do and they've got a promise to Naruto to keep. I don't see Sakura doing that, I think they'll be dealing with different things. Everyones eyes seem to be on Obito now.
So the gist of this statement is that Tsunade will be the one to fight whilst Sakura remains to the side to act as a healer for a collection of fodder that will likely have no significance in the future. Honestly, her enhanced strength and Katsuyu's acid would be much more effective in this battle than anything the generic fighting force can produce.
That's not a promising indication of Sakura having finally surpassed her teacher.