World bosses? Check, including one that requires a legendary cape to access (and who drops a pair of shoulders I'm invested in) as well as rare mobs that anyone, even Horde and Alliance, can work together to bring down and get some loot. If you want to make friends with Emperor Shaohao, run around attacking everything in sight, or just check out a new landscape the Timeless Isle has things for you to do. If you want, you can even click the Censer of Eternal Agony and flag for PvP even with people in your own faction.
By necessity I'm leaving out tons, so head on over to Blizzard and check it out for yourself.