"‘Kolaveri Di’ Goes Viral. But Why?", WSJ 11/22/2011; "Kolaveri di next big thing in popular culture", DNA 11/25/2011; "With millions of hits, 'Kolaveri Di' on song", The Times of India 11/25/2011; and so on:
According to the Samosapedia, kolaveri "means a murderous rage felt by a jilted or spurned lover but in everyday parlance refers to unnecessary anger" and di is the Tamil or Mallu version of "girl" or "babe". The video has subtitles, and an English translation is given here.