Dota 2 appeared in my Steam Account.

You can get it for free everywhere... xD

I believe that's just the spectator client, which is free.

Hey new guy. If its the Spectator client after all, add me. I have six copies.

It's not for free but Valve sent out hundreds of guest invites. If u need some more invites e.g. for your friends, add me !

Expect being flooded with invites in your inventory.

U'll have a spectator pass :P
U'll install the whole thing and when u'll start it, it'll ask u to put in a key or just WATCH the damn thing and not play it.

cant play but watch playing..

If you don't see Dota 2 Test along with Dota 2 in your game library then it's probably the Dota 2 spectator client. If you got the full game you will have both Dota 2 and Dota 2 Test added into your game library, and still will be in your library even after uninstalling the game.