I much prefer the Bayesian stupid filter because each one of us can tune it to our personal definition of stupid. And it makes stupid disappear instead of highlighting it.
Not just trolls but the opportunities for abuse are tremendous. Think about how political and religious groups could use this to sway opinions and quiet desent.
Another reincarnation of crit.org. Wikalong is still online, but it's gratuitously incompatible with Firefox 3 (which is Firefox's fault, not Wikalong's.)