Both ARE possible, according to my best knowledge, so it wouldn't be wise to be too sure in any direction.
According to the technically correct, but completely useless, lesswrong style rationality you are right that it is not wise to say that it is "almost certainly bullshit". What I meant to say is that given what I know it is unlikely enough to be true to be ignored and that any attempt at calculating the expected utility of being wrong will be a waste of time, or even result in spectacular failure.
I currently feel that the whole business of using numerical probability estimates and calculating expected utilities is incredible naive in most situations and at best gives your beliefs a veneer of respectability that is completely unjustified. If you think something is almost certainly bullshit then say it and don't try to make up some number. Because the number won't resemble the reflective equilibrium of various kinds of evidence, your preferences and intuition that is being comprised in calling something almost certainly bullshit.
What I meant to say is that given what I know it is unlikely enough to be true
Well, given what you think you know. It is always the case, with just everyone, that (s)he estimates from the premises of what (s)he thinks (s)he knows. It just can't be any different.
Somewhere in the chain of logical conclusions might be an error. Or might not be. And might be an error in premises. Or might not be.
Saying - oh, I know you are wrong based on everything I stand for - is not good enough. You should explain us why a breakthrough in the self optimizing is so unlik...
...has finally been published.
Contents:
The issue consists of responses to Chalmers (2010). Future volumes will contain additional articles from Shulman & Bostrom, Igor Aleksander, Richard Brown, Ray Kurzweil, Pamela McCorduck, Chris Nunn, Arkady Plotnitsky, Jesse Prinz, Susan Schneider, Murray Shanahan, Burt Voorhees, and a response from Chalmers.
McDermott's chapter should be supplemented with this, which he says he didn't have space for in his JCS article.