I am quite sure of that during the experience in 1.06, the damage of a blizzard was amplified to up to 400 points when I possesed more than 4 water shards. However, I guess there must be more than solely damage buff of benefit in acuquiring those, for example, a boost in mana regeneration or arcane knoweledge. Hope next patch will fix it, since there is scant methods to accelerate the arcane knowledge production.