??
BitTorrent only works as long as at least one peer has the bits you need. The only way to insure that is to host a permanent seed. The Video Toaster sources do not share the same level of popularity as World of Warcraft or Lady Gaga, so in all likelihood, Bill would have to seed the ISO image indefinitely. In any case, he's already said bandwidth charges weren't the impetus for the change, although he certainly implied that at the beginning. ;-)
EDIT: Mini-rant not directed at anyone in particular: We all pay for bandwidth, and the only "winners" are the large telcos, who whine whenever anyone tries to use the bandwidth that's already been paid for.