StarROM has the most up to date build of WM6.5... 5.2.21202..
very nice stable rom
however that one has rhodium manilla in it (which works pretty well) so i dunno if you wanna try it...i suppose you could just disable it once you install the rom?
try it you'll like it
http://forum.ppcgeeks.com/showthread.php?t=63044