I still vote YES on adding the sex sites (in a separate DNS feed).
(1) It seems like all the technology and know-how is in place to do this... maybe with a little tweaking, but nothing different than what has already been done elsewhere.
(2) It would be a separate list and its use would be completely voluntary. Therefore, this seems to me to be MORE a question of "are there sufficient YET votes to make it worthwhile"... and NOT so much a question of comparing the "yes" vs. "no" votes because the "no" votes can simply choose to not participate... which is easy.... simply don't do anything different from what you are already doing.
(3) Its purpose and scope could easily be explained on the SURBL.org site in its own page. It could even be omitted from being mentioned on any other pages to avoid confusion.
Rob McEwen