Steam is already competing with very strong entrants (Amazon, Gamestop/Impulse, Gamersgate), and seems to be doing well. Microsoft hasn't exactly hit the ball

Steam is already competing with very strong entrants (Amazon, Gamestop/Impulse, Gamersgate), and seems to be doing well. Microsoft hasn't exactly hit the ball out of the park with Xbox Games-on-Demand, I'm not sure how much they really have to worry here.