Fury Warriors always had a similar thing to Frost Death Knights, having two "sub-specs." But in 7.0, Fury will fully embrace Titan's Grip to become all about dual-wielding two-handed weapons. To be fair, Fury's rotation was not nearly as altered by its choice of weapons as Frost, and going single-minded fury always felt more like you were trying to be contrarian than anything else. Fury gets to do something no other spec in the game does, so why resist it?
2 Fast 2 Furious:
Fury retains its Enrage mechanic, which it kept for itself in Warlords after it had previously been something all Warriors used. But Enrage now functions slightly differently. Getting Enraged increases your attack speed by 100%, but it also increases the damage you take by 30%.
Your Mastery still increases the damage you do while Enraged, but the attack speed focus will help you generate significantly more Rage while you are in your Enraged state.
Enrage lasts only 4 seconds.
You actually only spend Rage on a couple of abilities.
The primary one is a new ability called Rampage. This costs a whopping 85 Rage, causing you to make 5 strikes in quick succession, dealing a large amount of damage and then automatically enraging you.
Whirlwind is still your AoE Rage-burner, and causes your next Bloodthirst or Rampage to hit 4 additional targets for 50% of their single-target damage.
Finally, there's Execute, which which costs 25 Rage and deals a bunch of damage to targets below 20% health (unlike Arms, there's no "burn more Rage if you have it" component here.)
Bloodthirst is still the ability you'll hit on cooldown (4.5 seconds reduced by Haste, I believe) that generates 10 Rage, heals you for 4% of your max health, and Enrages you when it crits.
Raging Blow is now free, and instead generates 5 Rage when it hits, but can only be used when you're enraged.
Finally, Furious Slash doesn't generate Rage, but it costs nothing and has no cooldown, doing light damage and then increasing the critical strike chance of Bloodthirst by 15%, stacking up to 6 times (so 90%, which should be a guaranteed critical strike when you factor in base crit and whatever you have on gear,) but this buff is consumed when Bloodthirst does crit.
And the Rest:
You still have Charge, Heroic Leap, and plenty of utility stuff. You do not, however, have Victory Rush anymore, and in fact you'll mostly be healing via Bloodthirst.
Battle Cry is a new 1-minute cooldown for both Fury and Arms (might also be for Protection) that gives you 100% crit for 5 seconds - which should be extra useful for Fury, given that it means guaranteed Enrages.
Bladestorm is also baseline for Fury and Arms, as a cooldown you'll want to use in AoE situations.
My general understanding is that you're intended to use Rampage to spend your Rage, and then build it back up quickly with Raging Blow and the increased Rage generated by auto attacks during the Enrage, which will then put you near where you need to be to cast Rampage again. You actually get a spell alert when you have enough Rage to cast Rampage. You'll want to hit Bloodthirst on cooldown and fill in with Furious Slash whenever you can't do anything else.
I do wonder a bit about whether it's better to cast Rampage during an enrage if you can, given that it does so much damage - probably more than Raging Blow. But if it's not up, I'd guess RB is what you want to use while Enraged.
I will say that without Vicotry Rush or some of the great Arms survival talents (like Second Wind,) Fury definitely seems less capable of solo questing than Arms, though you can of course supplement yourself with food and bandages. In group situations, though, it'll totally be a matter of preference. If you want to be a blur of slashing swords, Fury definitely lets you do that. So cry havoc and let slip the hogs of war.
What was that? "Dogs" of War? Well I say hogs.