I read a fan theory related to the whole "Karin" DNA thing. There are panels showing Sarada being ill, a panel of her BEFORE she was ill, and a panel after. She wears no glasses before the sick panel, yet has them afterwards. Some people theorized that Sarada might have a serious illness her mother wouldn't be capable of healing (such as the illness Itachi had), yet Karin would be able to. The illness had advanced to harming Sarada's eyesight, which required her to wear glasses, and she has Karin's DNA.
I don't know, I thought it was an interesting theory. I don't really believe that Karin and Sasuke had a daughter under conventional means, especially with how Sasuke left Sakura in the last chapter of the manga.
Anyway, hopefully there's some Shin pounding going on in the next chapter.