I'm by no means a pro, just an amateur, and it's been a long time since I played vanilla wow, but my build was something similar to this:
http://www.wowprovider.com/?talent=1121 ... 3d33012100It's not set in stone, and it may even not be optimal, so feel free to "tweak" it to fit your fighting style better. For instance, instead of speccing into precision and dual-wield specialization to make your off-hand more viable, you could instead specc into parry and reposte to be able to disarm warriors. But the issue here is that even though I'm told that in PvP most of your damage comes from yellow attacks (abilities) I've always felt that the extra off-hand damage helped a lot, especially since with this build's major selling point is stunlocking, which means that you'll have more time to stand there and let your auto-attacks do damage as well, and the fact that as a rogue you'll try to always be behind your enemy means that there will be even less chance of you parrying someone than you already have, so while it sounds good, in practice I've rarely ever been able to disarm (but if you do, then it helps A LOT with melee classes and hunters).
This also does not give you any high damage abilities, so you may want put some points into eviscerate in assassination to make it more damaging, but the only things you'll be able to trade for eviscerate are blade flurry (don't) or dirty tricks/hemo (again, reluctant - reducing energy cost of anything is always preferable to me and hemo is a lower-cost alternative to sinister strike). I used hemo if I needed the combo points or sinister strike if I wanted to put more damage in.
All in all, I tried to reconstruct it from memory, and this seems like something similar to what I used. Feel free to tweak it to your playstyle - the major point is of course "Mace specialization" and subtlety (subtlety has some talents I just CANNOT do without in PvP, such as Camouflage, which doesn't seem game-changing, but it is).