The more I read this, the more I think it'll happen, for two reasons:Originally Posted by ASSpirine
a) Right at the beginning of the battle, Shikamaru said "this time I'll get my priorities right". Priority was to kill Kakuzu first. Though it looks like they're falling apart from Kakuzu's awesomeness, the mention of that role hints they've still got a plan in mind. As far as tactics go, you have an ultimate goal, and depending on the situation, you adapt your means to achieve it.
b) Second point has to do with the preview {Preview Spoiler}The preview shows Hidan no longer in his Black&White ritual mode. From what we know, he only turns back to normal after the designated person is dead, or suffers a mortal injury. Since he's already black&white, we know he ingested blood. Therefore, someone died. And if you watched the preview, you know it's not Shikamaru.[END SPOILER]