The Haloplayers.Com group sent me this PR just recently:

After an outstanding response to private invitations to join forthcoming Halo Leagues, which went out privately to major Halo-Clans last week, Haloplayers.net has now officially announced 3 Halo leagues publicly.Any Halo-Clan may provisionally enter one or more of the 3 leagues. USHL, EHL and UKHL. More information can be found from http://www.haloplayers.net

The Haloplayers.Com group plans for their site to be similar to the popular Tribesplayers.Com. It'll be interesting to see how things develop when Halo is nearing completion.