I think it is quite to clear to see that he is a Te user. He cares only about the facts, evidence and empirical data, whilst rejecting his own personal values and feelings. I've seen him typed as both NTJ types in the past, but I think Te really is his most prominent characteristic, and inferior Fi makes more sense than Se, thus I type him as ENTJ (although it's not ridiculous to suggest that he uses Si-Ne instead).
If anyone here has read The God Delusion, it shows how prominent the function is by frequently citing works and quotes by peers to back up arguments as well as nearly constantly working with exterior frameworks and systems rather than his own personal logic, which would indicate Ti.
Plus his attachment to Darwin and his theory of Natural Selection, I think because of his Te adhering to an exterior framework, cements my evaluation of ENTJ, or at least, a dominant Te user.
I've provided this video (not only because it is hilarious) particularly for the interview that begins at 0:16, and sections of which are scattered throughout (1:15, 2:09, 3:29).
I think at 1:15 especially, shows inferior Fi, with his inability to answer such a question because of the requirement to make a personal subjective judgement and interpretations. This kind of question is the exact opposite of Te. At the end he also states that "I see myself", which might also indicate Se, only seeing what concretely is.
Again, at 2:09, he shows Te by mentioning the dictionary, an external system.
As for Enneagram, I'm not too sure, although I'll take a guess and say something along the lines of 5w6-1w9-2w1. No idea about the variants.