Onoki, is the most likely candidate. Tsunade's a maybe, but I think the chances are lower since Naruto's not there to witness it (for some reason, I feel like if she dies, it will with Naruto as witness).
I don't see any reason for Kakashi to die -- it already happened once, so it wouldn't have the same impact.
Gai could die, kamikaze style, but only as an excuse to show us the 8th gate. I'd like to see what that's all about, so I guess a little part of me is rooting for Gai to die.
Given recent events, I think Kabuto will live. At least he'll live long enough to see his adopted brother again. I'm curious how he'll react to learn that Kabuto is basically co-responsible for the war. This is Naruto, though, so most likely he'll just be cool with it.