UPDATE: Our own Bill Murphy reached out to Blizzard for comment on this story. This is the response we received in return:
Thanks for reaching out to us. The Public Test Realm provides our players with access to content that's currently being brainstormed, developed, and tested, oftentimes many months (or even years) before release. Many times this content never even appears in the live game. While we have exciting plans for the future of World of Warcraft Battlegrounds, we don’t have any additional details to share at this time, including if and when any new content on the PTR will become available.
A new rumor (and a credible-ish one too!) has surfaced at VG247.com that Blizzard will be introducing a MOBA-like feature with the next World of Warcraft update. Called "Defense of the Alehouse", the feature has been 'leaked'. What shows is a top-down map that seems to allow up to ten players to take part. What do you think?