That said, my usual reply to the pro-death argument is some form of "If a rogue scientist accidentally released a nanovirus that kept everyone alive and healthy for a thousand years, would you support a policy of artificial death to maintain the status quo? If not, why not?"
I use the baseball-bat-to-the-head analogy, that if people were hit on the head with a baseball bat twice daily, after years they would come accept it, after decades they would come to believe it is good, and after generations they would develop clever and complicated arguments as to why it is good and why it should continue. But would any of those arguments convince you, now, to take up a regimen of baseball bat strikes to the head?
I think I stole that almost word-for-word from somewhere else on this site, though.
The original was Eliezer himself, in How to Seem (and Be) Deep. I'm more fond of TheOtherDave's analogy, though, since I think the baseball bat analogy suffers from one weakness: you're drawing a metaphorical parallel in which death (which you disagree is bad) is replaced by something that's definitely bad. Sometimes you can't get any farther than this, since this sets off some people's BS detectors (and to be honest I think the heuristic they're using to call foul on this is a decent one).
Even if you can get them to consider the true payload of the argum...
Last Wednesday (2010 Dec 01), BBC Radio 4 broadcast a studio discussion on the question: "should we actively try to extend life itself?" The programme can be listened to from the BBC here for one week from broadcast, and is also being repeated tomorrow (Saturday Dec 04) at 22:15 BST. (ETA: not BST, GMT.)
All of the dreadful arguments for why death is good came out. For uninteresting reasons I missed a few minutes here and there, but in what I heard, not one of the speakers on any side of the question said anything like, "This is a no-brainer! Death is evil. Disease is evil. The less of both we have, the better. There is nothing good about death, at all, and all the arguments to the contrary are moral imbecility."
Instead, I heard people saying that work on life extension is disrespectful to the old, that to prolong life would be like prolonging an opera, which has a certain natural size and shape, that the old are wise, so if we make them physically young then old people won't be old, so they won't be wise. Whatever cockeyed argument you can construct by scattering into a Deeply Wise template the words "old", "young", "wise", "decrepit", "healthy", "natural", "unnatural", "boredom", "inevitable", "denial", I heard worse.
If I can bear to listen again to the whole thing just to check I didn't miss anything important, I may write something on their discussion board.