The tokens drop from Black Temple and Mount Hyjal bosses, so are a little bit of a pain to get hold of if you are a solo player, however most can be done with two, or three people.
Tier 6 also reintroduced the matching belt, wrists and boots for a set bonus, which we saw in Vanilla but was missing throughout The Burning Crusade, these tokens drop in the Sunwell Plateu, which again will need a few people to complete.