That seems to be the trend most of the way around the globe, apart from Asia where there is a lot of BitTorrent. BitTorrent traffic levels are in decline.

CacheLogic has noted a significant shift in the balance of traffic levels associated with the main P2P protocols through our unique access to actual web traffic data throughout the world,

It's very complex - P2P is very large objects, very long sessions, undocumented protocols, it's very demanding. Your average copy of Squid or Microsoft ISA is not capable of dealing with P2P.

One reason people are looking at P2P is because it gets them away from CDN - content distribution networks.

History is repeating itself. File-sharers moved from Kazaa to BitTorrent and now to eDonkey.

The Whack-A-Mole game continues, ... The authorities go after one [peer-to-peer] system and another one pops up.