The game itself is still floating in a managed beta state, but Valve has publicly released the Dota 2 Spectator Client: a standalone install now available from Steam that lets users view live or recent matches of their ambitious multiplayer online battle arena (MOBA) game.
The official Dota 2 blog
reveals that they've opened the spectator client up to everyone to let as many people get a first-hand look at the upcoming The International
tournament -- the Valve-hosted Dota 2 eSports event that kicks off in Seattle on August 31st.
You will be able to watch any Live or Recent matches plus all of the upcoming The International right inside the client. Every spectator feature is enabled, including Player Perspective, Commentators and Directed view.
The blog goes further to explain that the spectator client will transition into the full game client "once we expand server capacity enabling Matchmaking, Chat, Persona, etc.", perhaps hinting at an official launch in the not too distant future.
Steam users not already in the Dota 2 beta can nab the spectator client here on Steam