For the Paladin whoever prioritises Blessed Hammer, important to note is the Concentration aura from the skill tree. Although not shown by Blizzard this increase skill damage of Blessed Hammer which I think is devious. Take care though that low resistance of elements and damage cold damage all decrease casting rate of Hammers, so Kira's Guardian plus Raven Frost is a must on all Blessed Hammer Paladins.
(0perator impersonation - how did I do?)