On LW, you can find discussions about the ethics and desirability of life extension in posts on cryonics. But it's also a well-established academic topic. Bostrom's papers on life extension are probably interesting to the LW crowd:

• The Fable of the Dragon Tyrant (this has been posted several times on LW)
• Recent Developments in the Ethics, Science, and Politics of Life-Extension (a review of this edited volume on life extension)

(Bostrom is, of course, an advocate for vastly extended lifespans. But he does give references to academic papers and popular writings with different conclusions.)

I think a literature review, rather than the current discussion post, would be much more appropriate.