FC4->FC5 upgrade options

[Jack Howarth]

    What exactly are going to be the final upgrade options for
moving a FC4 machine to FC5? I take it from previous messages
here that upgrading via yum will not be recommended. Will a 
standard upgrade install over an existing FC4 installation work?
I assume the promised ability to do an archive and install ala
MacOS X hasn't made it into FC5. Is that correct? Linux is never
going to make significant headway on the desktop until we get
rid of the need to wipe and reinstall every time a system release
occurs.
         Jack