IE for Mac won't play it. Nor will Flip4Mac. I don't know of any Apple ap that will. There is an increasing number of web video providers who apparently just writing off Mac users as viewers. It's not just MSN. It seems like MS is slowly but surely killing off web video playback for Apple users by convincing web media providers that the miniscule numbers of Apple users are not worth spending money on. To me this is a very serious threat to Apple.