Now this isn't going to be a post where I ask you guys to recommend me builds. This is a post where I'm going to recommend to you guys a very nice prot build.
When I was leveling as prot, I kind of just picked random talents as I leveled to try things out. By the time I'd been 80 a little while I was ready for a lean and powerful spec. No wasted points, all killer no filler. After some looking around and trying things out I found what I consider to be the best spec for most current talent.
Looking down the prot tree there's a lot of fun toys. Improved Spell Reflect, for instance. Reflect spells cast on party members? What a life saver! Until, of course, you realize that you can't spell reflect most boss' casts and the range on Imp Spell Reflect for party members is like 15 yards or so. After realizing this, you should see that there's only one place where that talent is worthwhile, Malygos phase 2 where your party will be grouped up on top of each other in those bubbles and you can spell reflect the flying mobs' casts. So yeah, it's pretty well worthless in Naxx and Obsidian Sanctum and most heroics (where you'll only need to reflect casts on yourself).
So after talking about Imp Spell Reflect entirely too much, here's my spec.
Arms:
3 / 3 Imp Heroic Strike - good for almost all tanking situations. Cheaper Heroic Strikes? Oh yeah.
5 / 5 Deflection - 5% parry is worth almost 250 parry rating! Not subject to Diminishing Returns! A nobrainer.
2 / 2 Imp Charge - more rage to start a fight with, oh yes. I try to always start a fight with a charge.
2 / 2 Impale - wait what? more crit damage == more threat, great synergy with incite
3 / 3 Deep Wounds - waaaait... WHAT??? hell yeah! 10% more damage compared to the 3% I lose from not maxing cruelty + more threat!
Fury:
3 / 3 Armed to the Teeth - more ap == more threat
2 / 5 Cruelty - just doesn't compare to Deep Wounds :(
Prot:
Well, instead of listing every talent I'll just go over one.
2 / 5 Shield Specialization
Now, I know what you are thinking. Giving up 3% more block for more threat? More damage? Gotta be retarded, right? WRONG!!!!!
Now, there's an issue with Shield Specialization that is not immediately apparent. I'll make a little list to show it.
We have 5 / 5 Deflection which is worth 5% parry or almost 250 parry rating before diminishing returns.
We have 5 / 5 Anticipation which is worth 5% dodge or almost 200 dodge rating before diminishing returns.
Then we have 5 / 5 Shield Specialization which is worth 5% block or about 87 block rating...
So now you hopefully see the problem. 5 / 5 Shield Specialization is not worth the itemization points you'd spend on Block Rating! It's pretty crummy. To match the Parry talent it would have to increase block by 15% or thereabouts.
So, now that we know Shield Specialization isn't worth the talent points you spend it on, it becomes clear how to spec your prot tree. Now, I know some people prefer 3 / 5 Shield Spec and to give up Vigilance but I like Vigilance so I didn't do that.
Here's a link to my talent tree so you can see how I finished up the prot tree.
http://www.wowarmory.com/character-talents.xml?r=Mug%27thol&n=Hierax