Anyone is welcome to take the bits from bittorrent and then provide FTP, HTTP, etc. But the problem is that anything on download.fedora really needs to be mirrored. And we've got a massive amount of content to be mirrored; making it available in more ISO-type chunks is duplication of what they're carrying and makes for less than happy mirror admins.
Jeremy
However, this means that many users will have to rely on the mercy of some volunteers who might step up or not, and they will be essentially cut off from official media supply. This is a big penalty and really prone of driving users away from the distribution. The example of "Fedora Unity" already shows that your suggestion is far fetched and unrealistic. I haven't found a single site yet which is mirroring the respun images.