H3 ANW is actually released now.
http://www.harpoonhq.com/phpBB2/index.php
is a forum where you can discuss the game and whatnot, mainly H3 players (and the actual designers, and scen makers etc etc). Small but "effective" group.
http://www.harpoonhq.com/phpBB2/viewtopic.php?t=3691
Is the specific "ANW released" thread.
http://www.matrixgames.com/forums/tm.asp?m=1160564
Is the official publishers (I think) forum thread.
I play harpoon classic myself though.