I added the Category:History link in at the head of the page... other
useful links related to releases could go there... and the current in
preparation entry could also have a link to the "planning" page when
that is made at any time for convenience.
I know search can find these sorts of pages, but I personally like a
nice index page too.
I stopped adding entries at the point where it did not seem to have
much useful information about the releases or where I did not know
the release dates from http://dist.opensimulator.org But others may
have the information and be able to improve the page.