If I load this version and later run `yum update` after Fedora Core 5 Test Release 3 and later once the Fedora Core 5 Final version is released will I pull in the updates?

So either I can do this
FC5 Test 1 becomes FC5 Test 2 (after `yum update`) becomes FC5 Final (after `yum update`)

or FC5 Test 1 update FC5 Test 1 build XXXX (or something like that)

I ask because I seem to want some of the upgrades from FC4 to FC5 but am having problems upgrading individual packages. KDE 3.4 to KDE3.5 for instance.

Thanks for the information

That would be a yum upgrade , not yum update. It should work but you need to let yum know what version you want to get rpms from. I guess there are fancier ways of doing this but, I just edit each repo to replace all $releasever with the version number.
For example:

name=Fedora Core $releasever - $basearch - Base

name=Fedora Core 4.91 - $basearch - Base

Then, I do a yum upgrade
After that is done, I do a yum update and make sure the /etc/fedora-release shows the new version.