When is a bug not really a bug? This is the conundrum that was recently addressed over at The Many Relms of Relmstein blog. Apparently, WoW's Patch 2.4 had introduced a bug that prevented players from taking advantage of an exploit with pre-made teams in battlegrounds. It allowed pre-made teams to send out a scout to determine who they'd be battling next. As you can imagine, this is causing some unfair advantages between the two factions. But Blizzard quickly remedied that new bug, which in turn reintroduced the original exploit.
Read more about the details of this ongoing battlegrounds exploit over at Relmstein's blog.