As someone who tends to side with Chomsky in these debates, I think Norvig makes some interesting points. However, I would like to pick one of his criticisms to disagree on:

"In 1969 he [Chomsky] famously wrote:

     But it must be recognized that the notion of "probability of a sentence" is an entirely useless one, under any known interpretation of this term.

His main argument being that, under any interpretation known to him, the probability of a novel sentence must be zero, and since novel sentences are in fact generated all the time, there is a contradiction. The resolution of this contradiction is of course that it is not necessary to assign a probability of zero to a novel sentence; in fact, with current probabilistic models it is well-known how to assign a non-zero probability to novel occurrences, so this criticism is invalid, but was very influential for decades."

I think Norvig wrongly interprets Chomsky's "probability of a sentence is useless" as "the probability of a novel sentence must be zero". I agree that we've shown that it's possible to assign probabilities to sentences in certain contexts, but that doesn't mean that it can fully desribe a language and knowledge. This seems to me yet another case of 'the truth is somewhere in the middle' and would be weary of the false dichotomy that is put forward here. Yes we can assign probabilities to sentences and they can be useful, but it's not the whole story either.