(From Unholy Dps Thread)
Orc
Orcs have long been the absolute best race for Unholy dps, and they still are for Horde. 3 expertise when using an axe/fist, 5% pet damage, and a 15s boost to AP every 2 minutes is almost tailored to fit the spec. The expertise boost is based on weapon itemization available and the AP cooldown is quite decent (1170 at 85), thus being enough to place Orcs a step below Worgen if you're looking at the absolute best race, faction regardless. Still, Orcs are as solid a choice as ever.
(From Frost Dps Thread)
Goblin
It shouldn’t come as any huge surprise that Goblins, being a brand new race, are much better than average. 1% increased attack/cast speed is quite decent, and a resource-free nuke (or, alternatively, blink) on a 2 minute cooldown is free dps, pure and simple. Easily the best horde race for Frost, although the competition isn’t exactly stellar, and they would easily lose out to Worgen and, potentially, Draenei.