What’s the best spec for (tanking/DPS/PvP)?

A: Play the game, try things out, discuss. This is beta and this is a brand new class, there isn’t four years of back theorycraft and empirical testing for this class. There isn’t four seasons of previous arena history to base conjecture off of. There are a multitude of specs for blood, frost and unholy tanks, DPS and PvP, and the talent trees change every single patch.

Get out there and try it. That’s what the beta is for.