Long time no see TAC 
I'd say you cannot go wrong with a psi or fire poison corr.
maybe i was doing something wrong but i absolutely hate my psy/poison corr...it seems like something is wrong with psy...i rarely get scourge and overall do no dmg. da****?!
Try Dark/poison. Much better for PvP. -Tohit stacks with weaken, you get a heal, and has nice damage and you have some cheaper procs form the tohit sets(iirc)
You said you had a cold/son? ive seen thos ein zone to be pretty deadly. Also, son/dev wouldnt be bad either, but my advice it to try the new FOTM: Dark/Poison
@AresSupreme, Psy has delayed damage, and scourge is calculated when you fire your attack. Also, Psy is only particularly good when paired with other psy damage.
Psi/Poison is viable in 1v1-8v8 and zones. You can probably make fire work too especially with reactive.
I've read a ton of the changes since i13 so I'd thought I'd roll up a new Corrupter (looks sadly at his Energy/Sonic/Mu Corrupter)
What are the more effective (not duel) Corrupter builds fielded ? (Arena/Zone)
I was thinking Fire/Poison or Psi/Poison? Looking at Mids it seems PSI has an edge over Fire? I also have a 30 Cold/Sonic defender on the shelf and a 39 Sonic/EM blaster I'm working on too.
Many thanks, here's hoping the Devs will improve PvP if we just stay here and keep playing and asking questions.