Centos 4.4 to 5 upgrade too much of a pain

Apparently upgrading from CentOS 4.4 to 5 isn't as easy as updating the centos-release package and typing `yum upgrade`. This is unfortunate, as the computers that I have running CentOS are typically the ones I like to have a high uptime, so this means I need to take them down to run Anaconda. I guess that's just the way it goes this upgrade cycle (same for Fedora 7).