Well, as always, I´m keeping my desperate hopes up: Instead of preparing for Kabuto´s death by being beaten by the Uchiha-combo, the flashback is an attempt to show the strong "bond" between Kabuto and Orochimaru. Finishing with Kabuto turning into Orochimaru once the flashback is over, explaining it with "remember when Sandaime sealed Oro´s arms, but Oro got back his arms by switching bodies? Well, since Kabuto has real Oro-cells, these cells contain part of Oro´s soul, which allowed him to come back, even though most of his cells were sealed by Susanoo".
Come on!