Picasso Key Chains and Mona Lisa's Mustache

Marcel Duchamp

Have you seen the series "The Mona Lisa Curse" by Robert Hughes?  He makes some interesting points, but my favorite is his assertion that art is conceptually vulnerable.  In other words, it can be so viewed, in such a manner, as to loose significance.
Now, the artist in me disagrees with a most dramatic "NEVER! Authentic art has an internal incorruptible life!" The viewer in me though? She can't help scan her mental files of "Water Lilies" cutting boards,"Nighthawk" mouse pads, and "Starry Night" coffee mugs.
Of course, there are artists whose work focuses on that very discrepancy between a work of art itself, and its significance as a market or cultural object.  (Enter Warhol, et al.) But the point still remains that for everyone to have their Mona Lisa production must be increased.  In our age of mass production, it is difficult to appreciate a work of art simply for what it is in and of itself.
(Side note: Do you think this could be part of the contemporary appeal of street art, which is generally devoid of salable product and harder to repeat?)