I was looking for exact numbers for my shaman, there are the info I take for a lot of guides, recount checks, etc. Hope can help.
Gear stats priorities:
First you must cap your specials (Stormstrike & Windfury Weapon) : 9% hit required. We get 6% from Dual Wield specialisation so you need 3% from gear. At level 80 thats 99 hit rating to cap specials.
Secondly you want to make sure none of your attacks are dodged or worse parried. To do this you need Expertise, 26 Expertise (6.25%) means your attacks cannot be dodged or parried. At level 80, that means you need 214 Expertise rating. A lot of the expertise available comes from rings, neck pieces & trinkets as well as buff food, gems and enchants.
Third once you have capped your specials and your Expertise, you need to make sure that all those instant cast spells actually hit the target a missed spell is zero dps. To do this you need to cap your spell hit which is 17%. Now stacking hit rating is great because it helps your white damage too (due to merged spell hit and melee hit rating) which means that the 40% of your damage that is from regular swings of your weapons hit more often too.
In a raid you can expect to get a 3% hit buff from moonkin druids or shadow priests, this leaves 14% from gear. This means you need 367 hit rating or 341 if you are a Draenei. Remember that you don't need all that from gear you can get it from food buffs, gems and enchants.
Ok so having capped all your specials, expertise and spell hit (which is not something immediately obvious to most players) what now can I now look at the "normal" stats. The answer is yes once you have capped all three elements above go for : Crit, AP, Agi, Haste. More hit isn't a bad thing either but a lot less important once you have capped spell hit. What order you go for with Crit/AP/AGI/Haste will very much depend on your overall gear balance.