I got it on my main during the first week of WotLK when very few people knew what to do. That said though, I have managed to do it several times since then, including once or twice during cata. The other team just have to be really really bad and your team has to be really really good.
Now Stormpike Perfection and We Had It All Along though.... those are a real pain in the ass. I've managed to get them both once, on different alts, during the time achievements have been in the game..... fuck that zzzz