Blizzard announced this morning that the public test realms are back online with a new addition.....

Public Test Realms Now Open!
The Public Test Realms have reopened, and we invite all World of Warcraft players to participate in the public testing of patch 1.5, which introduces Battlegrounds to World of Warcraft! Read about the new Battlegrounds and other changes and additions to the game in the test realm patch notes.

For the complete article check out the official WoW site here.