Valve Announces DOTA 2 Spectator Client
Valve has announced the Dota 2 Spectator Client in preparation of the Dota 2 championships The International coming around.
Every Steam account with Dota 2 available will be able to access the spectator client. The client will let players watch any live or recent matches, and will showcase upcoming matches as well. All spectator features are also accessible, including Player Perspective, Commentators, and Directed view.
The Spectator Client is expected to become the full Dota 2 client once Valve expands their server capacity to enable matchmaking, chat, and persona functions.
(Source: Dota 2 blog)