I've been following quite closely but might have missed this. What is it that Jugo and Sugeitsu found in Oro's lair? See: http://www.mangareader.net/naruto/574/6.
Yes, it was revealed in the manga. The scroll is a Jutsu Scroll for
Shiki Fuujin: Kai, the method to unseal the Dead Reaper Seal.
It was thanks to this that Orochimaru was able to revive the 4 previous Kages, whose souls were originally sealed within the Death God.