It's tough to be in Chomsky's position, and it seems to me Pinker takes it to a somewhat natural conclusion. If language is a specialised faculty housed in hard-wired circuits, it seems highly unlikely that it emerged as a side-effect rather than get perfected by selection. Now, some recent EP proponents (Pinker's comrades), in the face of fairly airtight criticism, have backed away from the claims that specific modules are present in a person, for this or that behaviour, and are selected for, to a more mushier claim that an algorithm to manifest that feature is present and was arrived at via selection. Perhaps Chomsky can appeal to a similar idea when it comes to language.
BTW, the point Michael makes in explicating Chomsky on evolutionary research into language (i.e., there is no fossil record, so the arguments are often circular) is echoed in a larger context by Jerry Fodor w.r.t the whole EP programme.
--ravi