The prize pool will include loot chests filled with Nvidia Shield and Falcon Northwest Tiki PC combos, Nvidia GeForce GTX 660 Ti GFX cards, PlayStation Vitas with copies of Borderlands 2 Vita (once it's released), and lifetime passes to everything 2K ever has and will put out on Steam. One player will also win $50,000 in cash while four others earn scaled amounts from a second pool of $50,000.
If you don't win a physical prize, you'll still have a collective chance with other players at "unique in-game loot" by completing the loot hunt's Community Goals. The event's site describes these as daily campaigns of genocide against "a special type of enemy with that day's unique gun." If enough are slaughtered in the name of personal benefit, those involved will earn a special gun at the end of the week.
Only players in the US are eligible for the physical rewards, but the in-game rewards will be available to vault hunters worldwide.