Lol I still can't believe that some people still don't know that the Gokage is simply the five kages from their villages.
Gokage = Five Shadows or Hokage, Raikage, Mizukage, Tsukage, and Kazekage collectively.
OT: My guess is that they'll come to support the SA but split into groups where their efforts would mostly be needed. Like Tsunade, Sakura and the medical unit to focus on healing. A, and Onoki on the frontlines attacking the Juubi and such. Gaara and Mei as support, espically Gaara since he's pretty much verstible with his sand be it defence, offence, also any combat range.