As some might know, when Jim Shooter was editor-in-chief of Marvel, he had an edict in place preventing Jean Grey from being brought back to life. This was because he felt that anyone who killed as many people as Dark Phoenix needed to either be killed off or suffer for eternity. (If Claremont or Byrne had their druthers, she would have remained alive at the end of the Phoenix Saga, which was their original plan.)
Kurt Busiek, back when he was just a fan, was the one who came up with how to revive Jean Grey without violating Shooter's edict. That's why there's a thank you to him in the credits of the comic in which she comes back.
Recently, Busiek posted on his blog his original notes detailing the whole of his story idea. Providing context, he explains, "Sometime between then and May 1982, when I graduated college and sold my first script, I started taking notes for various Marvel series I hoped to write someday, to make sure I didn't forget any of my 'great ideas,' few of which were great, or even memorable."
Further background info on the document can be found at his blog.
creator: kurt busiek, group: x-men, publisher: marvel comics