i want to mention that
War Pirate :: Shaman WotLK Alpha Talent Tree
says that clearcasting does proc from LHW & HW, but only reduces mana costs for damage spells. This is the link the thread editor uses as well as the elemental wotlk discussion thread.
So i guess going for a 8/6/57 will at the moment be the best. 8 in elemental as i posted before because of splashdmg which i guess will continue in WotLK.