At first I felt that it would be crazy for Valve to not follow the successful model that LoL has laid down. I didn't (and still don't) think DOTA 2 can be as successful as it can be if there is a front-end price tag attached. DOTA 2 needs to be free 2 play. However, the game play of DOTA 2 does not feel suited for the LoL model. DOTA 2 shines by having all the heroes available for every player for every match. DOTA 2 will not work with a rotating pool of free heroes each week.
So how does DOTA 2 go the free 2 play route? Simple. DOTA 2 will be just that: free 2 play. I mean 100%, unobstructed free 2 play. Outside of mailing Valve a wad of cash with a funny note for Gaben, there would be no way for player's to spend cash on the game.
Sound crazy? Maybe, but I think Valve can justify the costs associated by the sheer volume of players it could bring onto Steam. Each Steam user is a couple clicks away from becoming another statistic on Valve's already impressive sales charts.
There is more to it than just bringing new users to Steam. Because not only would this move promote Steam, but it would promote Steamworks -- Valve's game developer tool set -- which further ties games and gamers into the Steam platform. Oh and Steamworks is 100% free for developers to use. If DOTA 2 turns into a smashing, world-wide sensation (it clearly has the potential) with Steamworks doing all the heavy lifting, it will further propel Steamworks into the game development limelight.
The stage is set for Valve to shake things up with DOTA 2. Does this mean a completely free 2 play DOTA 2? I believe so.