Bronze is a special currency that you can earn during the World of Warcraft Remix: Mists of Pandaria event. Since there are endless ways to earn it, there must be endless ways to spend it.
WoW REMIX: Mists of Pandaria | Overview & Features
Bronze can be used to purchase special gear for your Timerunner character, including rare and epic armor sets, transmog apparitions, mounts, toys, and other useful items. Plus, everything you unlock will stick with your character when they become a standard character at the end of the Remix event.
Got a bunch of Bronze dragging you down in WoW MoP Remix? Here are the vendors who will take it.
Bronze merchants can be found in every Infinite Bazaar in Pandaria. When you're looking at a specific region, Infinite Bazaars will be marked on your map with a house and hourglass icon.