In a few days, millions of users and potential users are going to download Ubuntu's latest child, Hardy Heron.
With all the latest press coverage and all the excitement for Ubuntu, I expect this to be the largest Bittorrent based download ever.
I can not imagine any piece of software legally (or even illegally) available via bittorrent that has ever created more Bittorrent traffic than Ubuntu Hardy Heron will.
What is you guess - how many millions will download it, how much of the overall available internet bandwith will we consume?
My guess: Existing user base might be around 30 to 40 million, of which 1/3 will use bitorrent to download the latest i386 .iso.