Anything can be art because art is everything, whether it’s good or bad. Art is meaningful. It could mean anything, everything, and nothing all at the same time. It makes our lives infinitely rich.
Art is always in a constant state of change. There are many different forms of it that are more prominent in certain time periods (–> http://arthistory.about.com/cs/reference/a/art_history_one.htm).
Everything starts with an idea, and basically, art is a very large, wide, and deep idea. There are always new ideas and with that come new artworks.
Art is Art.