Right. so i have been playing my rogue for over 6 years now. Raided more then what is healthy for anyone. (not to proud of that

i have never set foot in the arena before like 1 week ago. Done a random bg now and then. but never got into it.

i am kinda good at using my cooldowns and such now in pvp. But i have no single idea of stats.

I do know that i need 5% hit. and thats about it.

i am going for mutilate pvp and i think my spec is ok. Copied from a decent pvp rogue on the armory.

But what stats should i go for in full pvp gear ?
Agi>Haste>mastery> after hit cap ?
What about spell penetration, is that needed and if so, how much ?