Gear
Stats
Stat priority runs in the following order:
Hit rating (to cap) > Haste rating (to soft cap) > Spellpower > Crit rating > Haste rating > Intellect > Spirit.
Hit cap is 263 (237 for Alliance with a Draenei in their group). Otherwise, raid composition is not an issue, as we provide the spell hit debuff ourselves. Against a sub-83 target, talents are sufficient to reach cap, so hit on gear does not add anything. The current tooltip for Balance of Power is erroneous; it still provides 4% to hit and the hit cap is unchanged from 3.1.
The soft haste cap is the point at which your GCD hits the 1 second minimum with Nature's Grace up. With Improved Moonkin Form, Celestial Focus, and Wrath of Air Totem, this occurs at 401 haste rating. Missing WoA, it's 585.
As far as the remaining stats, spellpower, haste, and crit will always be preferred if you can find items with all 3. Spellpower is the strongest. Spirit and Int give small DPS contributions.
Exact stat comparisons of course depend on your current stats/talents, but a typical set of values might look like:
Spellpower: 1.4
Haste rating: 0.9 [1.5 if not soft-capped]
Crit rating: 1.1
Intellect: 0.6
Spirit: 0.5