The warlock Siphon Life, Soul Link spec is almost a standard amongst the warlock pvpers. This spec gives you life back almost constantly, while at the same time reducing damage taken thru soul link and sharing it with your pet. The few downsides to this are that it really has no direct damage implications, and is extremely susceptible to dispels and cleansing.
http://www.wowhead.com/?talent=Iq0rVRckoZbxczIiz0es
If you can manage to add nightfall in there, you could have an extremely more potent PvP spec as well! Due to the constant Corruption and Drain Life effects you’ll probably be using. This build was once used to comprise 80% of the top warlock areana teams in world of warcraft