Players will find these new Bounder's Tokens from mob drops, quests, and other places. Turn enough in to a vendor in Michel Delving, and you'll earn personal rewards from a nearby vendor. However, if the whole server works together to collectively meet a grand goal, then a second vendor will unlock to sell cool items like war-steeds, mounts, and other goodies. In addition, the server goal of Bounder's Bounty will grant everyone a persistent buff until the expansion releases and help to erect a new statue in the center of Michel Delving.
Speaking of the expansion, Roger at Contains Moderate Peril did a bit of file rummaging and came up with several possible maps from the expansion. Thanks to Andang for the tip!