Okay, so you are trying to decide between:
Prot spec and another to serve as both PvP/PvE
PvP spec and a PvE spec.
Let me say this off the bat, while Cata has reduced the difference between PvE and PvP specs (since you now HAVE to go 31 points in, and there are fewer talents to choose from overall), specs do generally vary by quite a bit between the two. By choosing to have one spec to service both roles, you are choosing to be underpowered in both roles. And if you intend to participate in endgame content (Raids or even heroics), you won't be warmly received without attempting to optimize your output.
If you go Fury, you're really going to want talents like Furious Attacks and Die by the Sword. Consider this PvP build.
Now compare it to the Fury endgame build
Blood Craze is a pretty good PvP talent, but only moderately goon in PvE (and that's only so as to take heat off of the healer). Luckily, Battle Trance isn't an amazing talent, so you COULD lose it without too much problem.
The loss of Executioner, though, is unacceptable in a PvE build. It's a great talent. But almost worthless for PvP. So that's a problem. And Piercing Howl is a wasted point if you consider PvE. Die by the Sword is absolutely required for PvP, but almost totally useless for PvE (because, unless something went SERIOUSLY wrong, you'll never be getting hit by parry-able attacks). Furious Attacks is useful on a few encounters in PvE, but that's it. But depending on your PvP goals, might be invaluable there. Though perhaps not if you are running arenas and have someone else providing the debuff. Meat Cleaver is necessary for a Fury build if they do any AoE (which they will). But largely useless in PvP.
And this, again, is only the points in the Fury tree--it doesn't even consider your last 10 points.
So, as you can see, it's going to be extremely hard to choose which talents to take and which to leave in a hybrid build. Because many of the choices are a significant loss if you intend to use the build for both.
Not to mention the fact that almost all of your glyphs will need to be switched for PvP and PvE, which is going to get extremely expensive extremely fast. You're looking at 60g just to switch specs.
The same is true for Arms, with one big exception. The actual points spent in the arms tree are largely the same. However, there are a few talents that PvP arms Warriors generally add to Arms (so it has more than 31 points) that PvE Warriors HAVE to place elsewhere or face a sizable DpS loss (Executioner and Incite being the most important).
If you are dead set on having a hybrid spec, go with Arms. You still have the same glyph issues, though.
That said, I heavily urge you to consider dropping the tank spec (assuming it isn't your main spec). Gearing in Cata takes time and effort--gearing two specs in PvE is a lofty goal. It's much wiser to choose PvE tank or DpS, and then go with a PvP spec. (Of course, this only applies if you want to PvP--someone who only intends to PvE will have more time to dedicate to gearing two specs).