This rebuttal has always bugged me because of the egregious error Norvig makes in his analysis of pro drop. The dropping of subjects in English matrix clauses (e.g. "Not gonna do it") is known to linguists as "diary drop", and is a totally different phenomenon from the dropping of subjects in so-called "null subject" or "pro drop" languages like Spanish. The most obvious difference is that diary drop is completely impossible in embedded clauses:
I think I'm not gonna do it. [good in English]
I think not gonna do it. [bad in English]
(Yo) creo que no voy a hacerlo. [good in Spanish]
To linguists it's immensely frustrating that someone who's considered by the compsci crowd to be a leader in the field of NLP can't even get some basic facts of linguistic analysis correct. "Linguists can argue over the interpretation of these facts for hours on end", Norvig says dismissively. But any competent syntactician could have explained to him in five minutes why his examples are irrelevant to the point he's trying to make.
The rest of Norvig's post just consists in misunderstanding what Chomsky is saying, as far as I can see. Chomsky is saying that statistical analysis alone is not sufficient to achieve scientific progress. I don't think Norvig actually disagrees with Chomsky on this point, but he seems to think that Chomsky is saying that scientists should never use statistical methods.
The real kicker here is that Norvig is an engineer, not a scientist. He's contributed very little to the scientific study of language, and yet is lecturing someone who's contributed vastly more on how it ought to be done. Of course, that doesn't necessarily mean that he's wrong, but it does grate. Not to mention that the Chomsy/O'Reilly comparison is little more than trolling – it hardly seems calculated to stimulate an intelligent response.