Does that mean the pages need to be rated PG13? I keep some info over there, but none of it is racy... I don't think :)
What I'll do is leave the main and project namespaces unprotected, while protecting a private namespace where racy stuff can be kept, along with User, Image, and Template pages.
Also, once someone has gotten into the wiki, they've seen several warnings. At some points I'm probably going to relax the PG-13 bit by necessity (for the games wanted forums, as one example).