The best part about this is that the funnier and more incisive he gets, the quieter and quietier and quieter the laughter gets.
Too bad that nobody will hear about this except the people who read Slashdot, the people who watch Comedy Central, and the people who watch C-SPAN on saturday night. In other words, the exact people who are most likely to already agree with what Colbert is saying. Everybody else, well, everybody else will just hear about that part the BBC covered-- you know, the bit where Bush demonstrated what a down-to-earth, wouldn't-you-just-love-to-have-a-beer-with-me kind of guy he was by getting up on stage with a body double and deliberately mispronouncing words.
Which means Colbert's little song and dance here doesn't really matter. All right, so somebody criticized the president to his face for the first time in four years. (No, Kerry at the 2004 debates doesn't particularly count.) Okay, so what? The 32% who still approve of Bush's job-- who are, after all, the only people who matter-- won't hear about this, and if they hear about it, they won't listen. The 2006 elections still will go to the Republicans, because even if everyone gets pissed off at Mr. Bush, they still won't like the incompetent, spineless democrats any better.
The Republicans will continue to hold congress after 2006; nobody will ever investigate any of the laws Bush has broken; Bush will quietly leave office in 2008, Iraq will someday eventually get electricity and running water, and talk show hosts and revisionists will nostalgically talk about what a great leader Bush was until nobody remembers him as anything other than a second Reagan. (And how well do you remember the Reagan administration? Yup, that's what I thought.) Nobody will remember that freakish, depressing third half of the Bush presidency where major american cities were destroyed and the President was admitting to impeachable offenses on national television and nobody did anything about it. Everyone will just remember that first, inspiring part of the Bush presidency after september 11, when Bush said that God told him how to lead the country, and everyone believed him.