In a few hours, updates for Fedora 8 and Fedora 9 will start hitting mirrors. These updates are designed to transition users from our old repo locations to new locations that have all our updates re-signed with a new set of keys.

Most users will simply need to apply the offered updates, and later apply any further updates, and verify/import the new GPG key.

The process to getting new updates is two stage.

Stage 1) Users configured to get updates from existing repos will see a small set of updates available in the next few hours/days. These updates include fedora-release, PackageKit, gnome-packagekit, and unique (for Fedora 8, only fedora-release is offered). These updates should be applied as soon as possible.

Stage 2) Once the above updates have been applied, your update tools (yum, PackageKit, pirut) will see a new repository and a larger set of updates available. This is your new standard flow of updates, that will continue to see new updates as the lifetime of Fedora 8 and 9 progress.

There will be further milestones in the future that involve redirection of release package repos to match that of updates, and removing of old gpg key from rpm trust.

For more details and an FAQ, please see
https://fedoraproject.org/w/index.php?title=Enabling_new_signing_key