The TODO list for the gtk-doc project is at Bugzilla,
the bugtracking system of the GNOME project.

Visit
 http://bugzilla.gnome.org/buglist.cgi?product=gtk-doc&bug_status=UNCONFIRMED&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED
to see what is allready requested,
or where you can help. :-)

To put an other request on the TODO list, visit
 http://bugzilla.gnome.org/enter_bug.cgi?product=gtk-doc