My wife and I went to the local museum of FA today and I kind of was contemplating this too. Not so much the social importance or role of art in society but what makes something important enough to be put in a museum. My wife said some of it is about the subject matter but mostly its about pieces and artists that represent a transition or birth of a style or technique. I think if art has any role its about continuing that push into new ways to express ones self.
Personally, I’d be afraid of projecting too much importance on my work might cause me to be too cerebral about it all. To me, art is just a vehicle for what is already inside me to come out, and as matt calls it an active meditation.