You can buy early access to Dota 2 right now for £25 in the Dota 2 store, contrary to Valve's earlier declaration that Dota 2 is free to play. On the Dota 2 item shop FAQ Valve say that at this stage "we don't really think of Dota 2 as a beta" any more, but haven't completely released it because they're "working on expanding our server infrastructure" first. However, you can circumvent all that with the Dota 2 Early Access Bundle , which costs £25 / $39.99
So, Dota 2 is essentially out now, with a cost attached. The bundle also comes with nine cosmetic items, but it's the early access pass that Defence of the Ancients fans will be paying for. The free to play version of Dota 2 will give everyone access to every hero and players will only put down money for cosmetic items to personalise the game. That sounds promising, and fair, but as things stand, that's not the deal. Previously players have only been able to access the beta through invites from Valve and other players.
When they do press the big red "release" button, Dota 2 may well go nova. The beta alone has already proven extremely popular on Steam and the next International event is already scheduled for August.