Roger Ebert (whose intellect I greatly appreciate) has created a bit of a kerfuffle by declaring that video games can never be art.
The basic disagreements seem to come down to a) arbitrary definitions of art and b) an unclear distinction between the act of playing and the items played with.
While playing a game of chess might not be art, the chess set itself could be art. Playing catch with the Mona Lisa might not be art (performance artists might disagree) but the Mona Lisa itself is, I think, art. Still, if dance can be art, why not the act of playing a game? Can figure skating be art, but not hockey?
That's a slightly poor analogy, but perhaps this is the central problem: video games don't fit any of the traditional categories we would stick things into. Campfire stories to books to radio. Street performance to stage to movies. Games don't really fit.
Maybe games are ultimately the extension of playing make-believe with a big chunk of art (even if it's only preschooler level art) latched on the side.
I don't know if games are art. I'm quite sure there is, or can be, art IN games. Personally I think arguing one way or the other falls between stupid and pointless. So I'll stop now.