Jamboxdotcom said:
if Portal wasn't "The Game", there never will be one.
and to answer your question: not until there are no more religious (or otherwise closed-minded) zealots out to cockblock the whole world.
Because you need to be religious to be close-minded, eh? Also, Portal is not the greatest thing the video game industry has put out in the past 10 years, let alone in the 30+ years games have been rising in popularity. Portal is a cult hit that is regarded largely in gamer circles, but sees little relevance in the mainstream (besides that irritable 'The cake is a lie,' reference).
What is art, exactly? Wikipedia defines it as such:
"
Art is the product or process of deliberately arranging symbolic elements in a way that influences and affects the senses, emotions, and/or intellect."
See, the thing is, playing a game isn't the same thing as watching a film or reading a book. Video games require input. Therefore, we essentially control the art. While I won't say that all the storylines, models, and graphics in the game wouldn't be considered art, playing them, is, and never will be, art.
Also, as previously said, citing the Mona Lisa and the 9th Symphony in your defense of video games as an art isn't the best way to go about things. We will not have "the game" until we have games as an art form itself.