I think the meta-interpretation is what's intended, but not in the ending kind of way - match it up with the graphic, it shows 4 episodes from each season, the fourth episode, halloween, christmas and paintball. So it's the third milestone of the third season and directly implies that they want to do 4 seasons…

Have you heard the electric version? There is no guitar during the verses and I think the jagged riff that kicks in during the chorus complements the lyrics quite nicely eg. http://www.youtube.com/watc…