Best race for a warlock PVP wise (Horde Only)?

Really depends on what you think will benefit you. Orcs for pet damage, stun resist and extra spell power. Undead for resistance to shadow and forsaken will(breaks fear,sleep,charm);extra trinket basically until 30 seconds. Bloodelf for the aoe silence, really effective vs casters( enough time for you to cc again ). And goblins for the extra haste and rocket boots to get away, especially from melee.