Claremont also stated in an interview that the way he saw the whole Phoenix story ending was at the end of the Universe you would see Jean as Phoenix and Logan would be waiting for her, and they would finally get their moment and their passion would ignite the next Big Bang.
Now hopefully that will never happen, because as a story it sounds really whack.
But, considering that we know Phoenix is all about rising from the ashes, it shouldn't surprise anyone if Jean Grey and her fiery bird eventually do make a return. Hopefully next time she'll know how to control the damn thing and won't get killed so stupidly as she did the last time (still can't believe Xorn [or Magneto if you ask Morrison] was the one who killed the Phoenix, that is just crappy storytelling right there).