Fedora 8, Limited updates to F9 Release, Possible?

[Frank Murphy <frankly3d-fedoracore@xxxxxxxxxxxxxxx>]

I have f8, and basically want to keep it as close to end-of-live.
Can I in the meantime when F9 is released, add in an F9 repo,
for specific update(s). That I may need\require?

I looked at the yum updating page:
http://fedoraproject.org/wiki/YumUpgradeFaq

but from what I gather, it would replace F8 with F9 repos.
I would like to have both, if possible.

Frank