I feel this way as well. So far his behavior on the mailing list has been quite disappointing however. I'm not holding out much hope for the possibility of reform, but he deserves his fair shot anyway.
Ryan, why don't you take the matter to ANI or RfAr? Perhaps some sort of probationary mentorship can be worked out? I feel that keeping Abu off Jewish-related articles would solve this problem, taking into account the fact that this user has not been given any chance to reform. Please assume good faith.