I'm not really sure what to think about the subservient chicken.
It is an ad for a junk food enterprize. It subtly makes us remember the brand, and associate it with positive, fun things.
This is classic PR work.
On the other hand, it's very funny, well-made, innovative and can certainly be considered net art.
There have been many artistic interventions related to commerce. I have myself participated in some (though I must say I was very reluctant and would only do it again if I was as financially desperate as I was at the time). Commercials won't go away. We might just as well accept this as a fact and at least see the less idiotic ones without the constant scorn we are so accustomed to. And make that chicken jump and run. And then - move on to more enriching things.
(for more discussion about viral marketing, go to Palladio)