For me, the Times Square attempt falls straight into the 'self-radicalized incompetents' category akin to the British airport attack or the JFK plot; it makes perfect sense to me that 'real' attacks will be rare and with minimal casaulties (I have argued that Terrorism is not about Terror and Terrorism is not Effective in the past, and now that I think about, supposedly there's a power-law governing terrorist attacks). As far as credible attacks go, I guessed from going through Wikipedia's categories of terrorist attacks by year that a better prior would be more like 1/3, not 1/2. But when I say 'obviously false' I don't mean that it's an insane prediction (if you read through the thread you'll see I do call out some predictors for making predictions which I consider 'on crack' - not naming any names here, but none of his seem any more likely to be true after the passage of a year), I just mean that it's objectively and clearly judgeable as wrong now that the year is out. This is a rare and valuable property, as one will learn after reading through a few compilations of predictions for 2011.