I'm at 296 on the armory atm. I haven't got any of the 100 seal mounts from Argent Tournament, none of the new PvP mounts, missing 4/5 world boss mounts, both ToT mounts, 3/5 crafted Panther mounts, 4 Glory achievement mounts, 9 TCGs, Aeonaxx + Poseidus mounts, the CM mount, M BH mount (and Archi) and the 5000 claw mount. I don't think it's a huge task to get in WoD as long as you've been on top of the relatively easier stuff to get :P
Plus there's going to be a heap more mounts in 6.2.2 which helps.