If you guys are expecting something along the lines of Mad T Party or Electronica, prepare to be disappointed.
This is nothing than standard fair Disney character entertainment to keep guests in the park longer. It's a character dance party, similar to the #IncrediblesSuperDanceParty in Tomorrowland, which runs pretty much about the same hours (I believe it's 5-10 there).
Nothing to see here folks. Just Disney trying to distract people from noticing that there's nothing to do in the park until Fantasmic! starts (or potentially the Frozen fireworks if those end up happening).