As you may have already read, Hoary backports will be Subversion (sorta CVS) driven, to allow multiple backporters, maximum uptime, and most efficient backporting. I plan to offer backports for ALL architectures that Ubuntu supports.
David Longo of Somnium Computing has allowed me to host the new Ubuntu Backports tree on his server. It'll be located at: http://cloud9.somniumcomputing.com:81/ubuntu/backports/
(Yes, the :81 is required -- he serves on a nonstandard port. APT handles it perfectly)
Example lines:
#stable backports
deb http://cloud9.homelinux.net:81/ubuntu/backports hoary-backports main restricted multiverse universe
#stable extras
deb http://cloud9.homelinux.net:81/ubuntu/backports hoary-extras main restricted universe multiverse
If you're beta-testing, add another pair of the above, only with "hoary-backports-staging" and "hoary-extras-staging". Again, this is for BETA TESTERS. We strive to mark packages stable within 7 days of backporting, so just hang tight!