Guys, If you had DotA2 on windows you can get it right now. Dota2 just came out of beta on windows and is now on a rolling launch (the reason for queue, they don't wan the game servers to be overloaded with new players since it's a free game).
Also the test client for linux is incompatible with the main client that's released on windows. You can only play with other test users.
I have never installed it on Windows, however I did receive a key from a friend so the game was added to my games list on the Windows side. After logging in on the Linux steam client, it was immediately available for downloading, so I assume it is just new players that need to wait in a queue.