I have to side with Bruno on this one, more due to the technical aspects though. BitTorrent is still horrible about killing many peoples connections. Either the high upstream usage kills the downstream performance, or the massive amount of connections BitTorrent tries to open slows down the router. And because most every broadband connection has a much slower upstream, the majority of the people connected will download what they want, and maybe send 15% of it back out to everyone else.

Blizzard has been using BitTorrent since day one to distribute World of Warcraft patches. And it has never gone well at all. Places like Fileplanet probably like it though, since it has driven more traffic to their site as they mirror all the patches. I looked into it one day, and for Blizzard to have a 500mb per month distribution to the users over something like CacheFly or Akamai, it would cost them a maximum of 10 cents per user.