I've raided as both Arms and Fury with decent gear from Ulduar and for my gear, personally, Fury has yielded superior DPS. It's not the same for everyone and the best way to determine this (beyond personal preference) is to plug your gear sets for both respective specs into the spreadsheet and figure out which is better. I believe that with BiS weapons (Depravity for Arms, dual Voldrethars for Fury) and the best gear possible in every slot, Fury will come out ahead. Not only does it scale so well with gear, the playstyle is far more forgiving in fights where you have to concentrate on your surroundings, as well as allowing for extra GCDs for raid utility like shouts, sunders, etc. It's entirely realistic to compete for high damage as a warrior of either spec, but I don't think warriors will ever again be the sort of undisputed top damage they were during Naxx.

As far as Armor Penetration goes, it doesn't really matter what spec you are. The spreadsheet will reveal your SEP values with a gear setup, and you gem accordingly. In my Fury setup, ArP drops below 1 SEP, but in my Arms setup it has an SEP value of 1.8. I think most warriors you see with certain BiS gear probably run with Greatness/Runestone; with that trinket setup you mostly gem Strength to maximize DPS because of the trinket capping the stat, regardless of talent spec.

Whenever people say they do more dps with Fury than Arms, I tend to believe it's because they haven't mastered the Arms rotation. Arms is much more complicated rotation than Fury so most people who switch to Arms and only hit buttons when procs happen tend not to do much dps as Arms. I've seen my own dps go up over the past two months as I've gotten better with the rotation. Just this week, I repositioned all my rotation abilities on my UI to be right next to each other and that led to another dps improvement.

BTW...the above dps discussion is single target only. Fury rules in multi-target fights like Razor and Thorim.

Quick question:

Does having 2 same speed weapons still give you 1 extra flurry charge or did they fix it?

Quickie.

Armor pen and sunder armor.

If say a full 5 Sunders are on a boss. Would the max Armor pen you need be 75% or still 100% for a full penetration of armor with the 5 sunders up?

Spell Reflect mechanic: The warrior gains a buff that allows for spell reflection. A spell is reflected upon finishing its cast, but the buff doesn't go away until the reflected spell completes its travel time. This means that any spell that finished casting on the warrior between those two times will also be reflected. I don't recall how it works with channeled spells such as mind flay, but I do know that every tick of the flay is reflected.

Sunders work independently of your personal ArP. So even if you are maxed out at 100% ArP, your dps will improve with 5 sunders applied to the target.

What should a warrior tank put on his shield if he doesn't need +20 defense rating? I'm looking to increase survivability.

Your best options are [Titanium Plating] or [Enchant Shield - Major Stamina].

The Protection Gear Quick Reference thread is a great source for these type of questions.

I'm still having trouble figuring out block: good, bad, indifferent?

So is Blizzard, so don't feel too bad about that. This post in Finalizing the Prot Warrior design is a good reference to the value of 100 SBV, which is roughly that of the Titanium Plating after 3.2.

I would take the Mace. Better Stats and Mace Spec is > Sword Spec, even in PvP in my opinion.