Very interesting question. It's funny, what this most reminds me of is the discussion on censorship in art: post, which is about Badiou's claim that censorship no longer exactly exists: that is, even though people are still very influenced by societal ideas of "good" and "bad" taste, there's no longer a  visible struggle between censored and permitted art. Crucially, people have the feeling that everything is freely available (although Badiou is hinting darkly that there's a catch).

In a similar way your example of Wal-Mart shows that people have the feeling that the distinction between the elite and Joe the Plumber is being erased, at least when it comes to being able to buy luxury food (or what people are told is luxury food, and what they thus develop a taste for). It seems now that everything is available to everybody. Of course, there is more to the story. At least in the case of food there are fairly concrete and easy to identify environmental problems which come from this attitude, not to mention the astounding effects on people's bodies.