It's not clear whether any of the changes for 8.10 will appear as
normal updates for 8.04 or not.

Looking at the 8.10 Features overview:
<www.ubuntu.com/.../810overview>

I don't see anything that couldn't/shouldn't be available in the usual
bug-fix/security-fix/enhancement process. In other words, I don't see
anything that truly defines 8.10.

Given that 8.04 received at least one (I haven't kept track) kernel
upgrade, there's no real reason 8.04 users won't continue to receive
them, too.

There are some issues with 8.10; see the Release notes:
<www.ubuntu.com/getubuntu/releasenotes/810>

If everything's working fine for you now, might be best to wait until
the dust settles down for more feedback here.