To be fair, there was no mention of an archive at the signup page,
Which sign-up page did you visit?
At http://www.redhat.com/mailman/listinfo/fedora-list (which is the page pointed to by the Fedora project pages) the top of the page reads:
About fedora-list
To see the collection of prior postings to the list, visit the fedora-list Archives.
[and provides a hyperlink to the archives].
--
Nigel Wade, System Administrator, Space Plasma Physics Group,
University of Leicester, Leicester, LE1 7RH, UK
E-mail : nmw@xxxxxxxxxxxx
Phone : +44 (0)116 2523548, Fax : +44 (0)116 2523555