Given Steve Jobs's disdain for games, it'd be funny if he conquered the market. Mobile is certainly capturing the handheld and casual market. I do wonder if it'll ever do something that overtakes or renders obsolete the console market, though. Maybe if Apple TV opens some new doors and has ludicrous penetration.
I think it's very possible that Apple could become the casual games industry. I don't think they will have as big of an impact on the hardcore gaming market though.