It is strange how people still seem to think this argument has something to do with doomsday - when what it actually about is a failure to make progress towards galactic civilisation.

I've pointed this out several times now - and so far nobody has even attempted to make a case for terminal setbacks - rather than roadblocks. Doomsday makes for better headlines, I guess.

[Update 2010-11-05] - K.G. now discusses such an case in her thesis - available from: http://meteuphoric.wordpress.com/2010/11/02/anthropic-principles-agree-on-bigger-future-filters/