User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-5850470-20121214224159

I think the POVs will include at least two out of three of the Romans. Hopefully we'll hear from Hazel again. Probably along with either Jason, Frank or both. For the number of POVs to be fair, there might be 3 in HoH, all Romans, and 7 in the fifth book. But you never know! :-) It will be interesting to see if we hear from Camp Half-Blood or Tartarus.