World-of-warcraft – Good Add-on to show coordinates in World of Warcraft

Let's start by summarizing what each race will bring to the table, leaving out the racials that are irrelevant or largely useless to a PvP warlock:

• Orc: A minor spell power boost every 2 minutes, a 5% pet damage boost, and a 15% stun duration reduction.
• Troll: 15% snare duration reduction and a 20% haste boost every 3 minutes.
• Undead: Dispel charm/fear/sleep every 2 minutes.
• Blood Elf: Instant AoE silence and minor mana restore every 3 minutes. (Note: Only has an 8 yard range, so you probably won't be using it against enemy spellcasters.)
• Goblin (available if you buy the Cataclysm expansion): A rocket jump.

In PvP burst damage is king, so the standout abilities (on paper) are the Orc's spell power or the Troll's haste abilities. The Undead's ability to remove charm/fear/sleep is also very useful, but there are items you can easily obtain which can do the same thing.

I'd be less inclined to choose Blood Elf or Goblin because I don't really view their racials as useful in PvP (again, as a Warlock), but honestly, you can excel at PvP with any race. It largely comes down to flavor and personal choice.

All three of the Blizzard Store mounts (the Heart of the Aspects, Winged Guardian, and Celestial Steed) work from Level 20 and 75 (slow ground) Riding Skill. They will not, however, allow the user to fly until the proper riding skills (225+ Riding, Flight Master's License/Cold Weather Flying) have been purchased (based on zone).

(Source: Wowpedia, Wowhead)