Well, not dead, but “sleep[ing] until the end of the world” rather suggests that he’s not going to do any more interacting with anyone else, which is (under a principle I've attempted to develop to deal with future personhood/identity/instantiating-people problems) equivalent to him being dead (unless he can make something out of the end of the world).

[I've thought about writing up said principle, but I'm not good at the sort of discussion it would likely prompt, and it's probably too simplistic. Anyone want to see it anyway?]