In 2011 during Gamescom in Germany, Valve decided to show off their upcoming action-RTS game DOTA 2 to the public for the first time via a pro tournament. 16 top eSports teams from around the world were invited to compete. In the end, the Ukrainian team Na'vi was the winner and its members received a whopping $1 million for their efforts.
Today, Valve announced that they will hold yet another huge DOTA 2 invitational tournament and once again it will be inviting 16 pro gaming teams to fight it out in the virtual battlefield. Na'vi is already confirmed to be returning to defend their championship along with the Chinese team DK. The other teams will be revealed in the coming weeks. And yes, Valve will be offering a $1 million grand prize again to the winning team for the 2012 tournament.
This year, the battles will be held in Seattle during the already sold out PAX Prime event from August 31st to September 2nd. Valve will stream the event live, free of charge, for those people who are unable to attend.
As far as DOTA 2 itself, it's still in closed beta testing. Valve said today that the game will be released sometime "this year" for the PC and Mac.