Battle.net announces Blizzard's Real ID party feature is now live in Word of Warcraft, allowing players to party up with their Real ID friends of the same faction, regardless of the realm they play on. The Real ID Website and FAQ have further details. Here's a bit:

When delving into the depths of Azeroth's darkest dungeons, it always helps to have some friends at your side... now you're able to issue a call to arms no matter what realm they play on. We're pleased to announce the new Real ID Party feature is now available for testing! This new feature will allow World of Warcraft players to invite their real-life Real ID friends of the same faction to a party regardless of the realm they play on, and then queue up for a 5-player regular or Heroic dungeon.