My 4 Lock/1 Priest team hit 70 last week and i've been grinding the battlegrounds nonstop. Since I play alliance (oh the pain....) I don't have WOTF to fall back on so mass fears are very, very painful for my team.

My locks spec:
http://www.wowhead.com/?talent=Iq0rrRfzoZbxczIiz0es

My priest is specced circle of healing - it's quite impressive with a lock group.

I try to use my felguards defensively, getting them on any player that can mass fear (warriors, priests and to a lesser extent other warlocks). That way if they fear, 4 of the fears are eaten by the pets.

Shadowburn is hotkeyed with the priests Shadow Wordeath to insta-kill anyone with less than 30% health that needs to die quickly. I castsequence my dots with life drain and that usually kills people about 2 seconds after the felguards stun them. The nice thing about life drain is that it locks onto the target no matter where they move, and with talents it drains for a *lot*.

Keep in mind I've just started, but AV (as Cepheus stated) is the real money maker. WSG and AB are a bit painful. Surprisingly, I win about 70% of EOTS though. I basically run from DT to BE towers and then police the flag spawn point and the rest is taken care of by PUGS. It just doesn't yield that much honor.

I'll post later with my findings as I haven't had *that* much experience with BG's yet.