Akussa sent us this ghost of Battlegrounds-past, which he and some guildies spotted being rode outside Karazhan. (You can see that it's relatively recent in that it's open to the Blood Elf race ... kinda.) The source of interest in the item comes because it only requires level 55, for a "very fast mount."
What some may have thought was a bug, a patch change, or even some kind of clever exploit is actually a remnant of times gone by. A veritable gremlin of the wonder-years of a battleground where -- to get the really good stuff -- you competed against every person in your own faction.
Back in that day, you'd try and outplay every person in your own faction to earn the top-dog spot. The better you did against your faction-mates, the higher rank you got. Then, in the old Honor system, if you got to Rank 11, you could buy your faction's honor mount pretty simply.
When they changed the mount system (making training expensive, and mounts cheap instead of vice versa), if you had the Rank 11 Mount. . .you got grandfathered to have the riding skill. WoW Insider extraordinaire, Daniel Whitcomb, reports still seeing the occasional 59 twink hanging out upon ancient War Wolf. I, on the other hand, ain't seen one in forever.