I've started reading Immortal Engines: Life Extension and Immortality in Science Fiction and Fantasy, ed. George Slusser, Gary Westfahl, and Eric S. Rabkin (Athens, GA, and London,1996). I'm interested to see what take the various contributors will have on how science fiction (in particular) typically regards immortality and radical extension.
My impression is that SF tends to be quite hostile to these ideas, though we can always be biased in obtaining such impressions (either by perceiving more widespread agreement with our own views than actually exists or by becoming hyper-alert to any disagreement with our views). The papers collected in Immortal Engines are from one of the highly respected Eaton conferences, so they can be expected to be of good quality - though themed conferences can, of course, lead to the publication of a lot of papers that are only tenuously on topic.
I'll plunge on, and I'll doubtless report more.