I wouldn't worry about losing too much, Andrew! I get the feeling that in discussions like this, the "underdog" obtains a distinct advantage, just due to being the "underdog". I actually had the opportunity of discussing this very topic with Subir over dinner. Being the argumentative person that I am, I jumped right into it, and had a bit of fun. My impression of his stance from that discussion is that he's far too hung up on this idea that the value of the cosmological constant that fits the observations is too small to be real. If it's that small, according to him, it must be zero. He did, however, seem to be rather reluctant to actually put forward his stance in the discussion, which I think I teased out as him believing that the observed accelerated expansion is just a feature of improperly taking into account the effects of the anisotropies. From everything I've read, it seems that has been pretty-well ruled out as a possibility. P.S. Kea, it looks to me like the most likely possibility is that they either made some significant error in their analysis, or worse. This is a pretty good description of the paper, though the really telling part is near the bottom of the post: http://scienceblogs.com/catdynamics/2009/07/is_cosmology_about_to_become_b.php As for my own impressions, let me say that the paper was *really* sloppily-written, and that alone raises my skepticism. If they're not taking the time to put the effort into the paper, I tend to worry that they have used a similar lack of care in putting the effort into the research. It didn't help that the paper was extremely light on details.