Playing Cataclysm Classic, I was in the Gnomeregan dungeon when the server shut down for maintenance. Logging back in after server reset, my character was just outside the Gnomeregan dungeon entrance. Out of curiosity, I entered Gnomeregan and walked back out. That sent me to Grom’Gol Base Camp. I jumped on the airship to head back to Orgrimmar. From the loading screen, I was immediately on the ground in Stonetalon Mountains and had to take a taxi to Orgrimmar.
Sounds like your position became invalid (not surprising given how you made it to Grom’gol). As a result you were put in the “corner” of Kalimdor - the 0,0 point, which is in the South-East of Stonetalon Mountains.
This has happened to me twice in the last 24 hours