Battlegrounds is here.
IGN has posted an impressions article covering World of Warcraft Battlegrounds. It goes something like this:
"You'll be entering an instance and will have to wait in a queue, and today it was a fairly long one, averaging 30-45 minutes before you could actually get in on the action. On the bright side, you don't have to stand there in the tunnel like a doofus--you can travel anywhere in the world, even another instance, and basically do whatever it is you would do, were you not waiting to get into the Valley. A small icon will be placed on your compass in the upper right-hand corner of the screen, telling you how long you've been waiting and when Blizzard estimates you'll be inside. You can also pop up a menu here that will allow you to leave the queue or enter another."
You can read the entire World of Warcraft Battlegrounds Impressions Article at IGN.