I have been playing 3v3 with Elem Shaman and 2x Destro Warlocks. I have won about 75%. I mostly lose against hunter or dual rogue teams.

Here is what I do...

First, send both felhounds to the healer (or dps caster if 3 dps team). I have a round robin macro setup for felhound silence. Then I use this cast sequence:

Shaman Warlock
1) EM+CL Immo
2) NS+LB Conflag
3) ES or FS Shadowburn

Target 1 should be dead or very close at this point. I then start a fear cycle on one while I take out the healer / ranged dps. Then kill the last one.