Upgrade to FC4 final?

[Harald Grossauer]

As far as I have seen there are no more updates for FC4test3, but FC4 
final is not released yet.

Just in advance: what do I have to do when FC4 final is released? 
Activate the appropriate repos, which are already configured in 
/etc/yum.repos.d but not enabled, and call "yum update"?

Will that be enough to get a "clean and complete" FC4 final 
installation? Or would it be better to download the ISO images and 
completely reinstall FC4 from scratch?