I would be very surprised, given Dumbledore's association with the Phoenix if he didn't come back in the last book. His unshakable confidence in Snape leads me to believe that he deliberately stalled Draco until Snape appeared on the scene to "kill" him. And if Dumbledore can come back, why not Harry? Harry may indeed be a horcrux, but perhaps a dip in the dirt can purge him of that.
Ooops, guess I'm not the only one tuned into the part about the Phoenix. Good work folks.
"Magic cannot bring dead people back to life
. Once youre dead, youre dead."