The first time I read the 'Dumby dies' scene I ran towards all those pheonix/ he isn't really dead/denial theories too but... mate.. sorry.. he is dead. Jo wouldn't mess around with death i reckon; dead is dead. You grieve for the rest of your life but you cannot bring them back. I think the whole pheonix shape rising from the pyre and the pheonix song, all the pheonix references, are more about hope rising from the ashes rather than Dumbledore rising from the ashes. Harry is hope not Dumbledore.