If you are interested in Internet traffic statistics (and as someone doing research in the area of data networks, I certainly am), there was an interesting "study" by CacheLogic on ISP traffic released recently (brief summary). Unfortunately, the presentation is an advertisement, but it still presents some interesting data. The most interesting claim is that BitTorrent is the application consuming the most bandwidth worldwide. I know SuprNova is popular, but I didn't realize it was that popular.
P2P traffic as a whole dwarfs everything else combined, which shouldn't be a surprise to anyone. These numbers make me think that someone is missing a huge opportunity here. What opportunity? I'm not sure, but there is obviously a huge demand for TV, movies and music over the Internet. This study reports that P2P traffic has done nothing but grow over the last few years. The authors of this study conclude that BitTorrent's popularity is due to the fact that the RIAA and others have been monitoring FastTrack (KaZaA), so users have jumped ship to another application. I'm not sure I agree, but this phenomenon was predicted by the DarkNet paper.