And now, when you do 25 man raids, you can exchange those emblems for the 10 man ones. Sarth and Naxx are puggable on most servers. Maybe not a full Naxx on some, but still, you'll get a decent amount of badges for easy reward.
Lets say you do Naxx 10, Naxx 25, Sarth 10, Sarth 25, VOA 10...