Mastery Bonuses

Shaman


Elemental

Spell Damage % 0.157 51 8.01 Increases the damage done by your spells by a percentage.

Spell Crit % 0.157 51 8.01 Increases your spell critical strike chance by a percentage.

Elemental Overload % 0.5 51 25.5 Grants a percentage chance for Elemental Overload to occur. Elemental Overload causes a Lightning Bolt, Chain Lightning, or Lava Burst spell you cast to trigger a second, similar spell on the same target at no additional cost that causes half damage and no threat.



Enhancement


Physical Damage % 0.157   51   8.01%      Increases all physical damage you deal by a percentage.


Melee Haste         % 0.157    51   8.01%      Grants a percentage of melee haste.


Nature Damage    % 0.393   51   20.04 %   Increases all nature damage done by a percentage.



Restoration

Healing % 0.157 51 8.01 Increases all your healing spells by a percentage.

Meditation 0.981 51 50.03 Grants a percentage of your out of combat mana regeneration from Spirit while in combat.

Deep Healing % 0.393 51 20.04 Increases the potency of your heal over time spells by up to a percentage

So with a 51 point Enhance build we are looking at 8% Physical damage, 8% Melee Haste, and 20% Nature Damage.  I'm still hoping for that last bonus to be changed to elemental rather than nature damage.
Looking at the most recent Saurfang parse about 19% of MY (not including totems) damage is Fire and 19% is Nature.  If you include totems then the % Fire damage goes up even more.