Roger Ebert is pretty smart.
He is saying that games can't be art because " they are bound by rules, points, objectives and achievements. When rules and objectives are eliminated, "it ceases to be a game and becomes a representation of a story, a novel, a play, dance a film. Those are things you cannot win; you can only experience them."
I think a lot of people got a knee jerk reaction to his words. Granted, games may not be an artform right now, but it doesn't mean they can't expand into that view.
Almost every game out there gets attributed to a few specific genres. Even off the top of my head if I do think of a few special games (Guitar Hero, Chrono Trigger or even
Flower) they represent a goal or objective to complete, not necessarily a story advancing the state of gaming.
Not like that's the huge thing. We still play games to enjoy them. Why do we need them defined as high art when that's not their purpose in the first place?