BlizzCon 2014 was announced earlier today and details for events at the convention have been trickling out since. The Hearthstone World Championship will pit 16 of the world's best players against one another: 4 from the Americas, 4 from Europe, 4 from China, 2 from Korea, and 2 from Taiwan.
The official Hearthstone site has the full details of the event, including how qualifying players will be chosen, which differs from region to region. It's interesting to note that some participants will be drawn from community-run events. The full rules for the event, however, have not yet been released.