Hi! I agree Socialtext 2.0 really is subpar. :-)
However, I'm coincidentally working for Socialtext, and am one of the main hackers of its Wiki Syntax!
I wonder if we can set up a Free-50 hosted account for the @cpan.org domain, and import the existing Perl 6 Wiki content: See http://www.socialtext.com/products/free50.php for details.
The gist is that all writers (not readers) need to be a CPAN author, which may have the nice dual side-effect of encouraging CPAN authorship and reducing spam.
If you'd be agreeable to such an arrangement, I can help importing the existing Wiki content to a hosted space just to see how it would look like, and work on lifting the 50-editor restriction if you think it makes sense.