Rogues have a 71% threat modifier.
Warriors have 80% in battle and berserker, and can talent another 10% for berserker.
Shamans get 70% after spirit weapons talent.
Druid cat form has 71%.
Paladin Fanaticism talent gives 70%

Casters generally talent for 20-30% reduction and have a higher cap. Arcane mages get 40%, shamans get nothing.

So rogues don't have anything special, they just don't have to spend any talent points for their reduction. They do have feint and vanish but Druids, mages, warlocks, and hunters also have threat reducing abilities.

It seems a lot of threat mechanics are being looked at so all of this could change in wotlk.