I wouldn't recommend going PoM Pyro at this time. Any spec you go into, I'd recommend going at least 50 points in at this time. With a PoM spec, that means you want 50 into arcane. But as arcane, if you're already that deep, you really shouldn't miss out on Arcane Barrage(that talent is hella fun). And what's more is that Arcane is incredibly PvP effective at this point in time.
My advice: Ignore Pyro. Go 51/10/0. If you have to PoM something, there's always fireball, and with the Arcane talents combined with Ignite(hence the 10 into Fire), you can't discount it. Add in the burst of an Arcane Barrage and start the chain with an Arcane Blast, and you'll find yourself not missing Pyro that much.
Alternatively, you could play around with a PvP fire spec(What I'm calling "Scorch Scorch Fireblast ZOMGHOTSTREAKPyro"). Playing around with it a bit, it has potential though I'd still recommend an Arcane spec.
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