The objective was not to rid ones system of WBEL packages or markings it was to make your WBEL system so it could use CentOS repositories. Except for a couple packages that whitebox upgraded that didn't really need to be upgraded. At the time I wrote migration document John Morris had been AWOL on updates for nearly 2 months.
The system will be not fully working. Various errors may occur when using mixed packages.
As the instructions are written your system will continue to function properly, however, up2date will still use WBEL repos while yum will use CentOS repos.
Mixing packages among EL3 real or clone isn't really a big problem I have machines that started out as RHEL 3 ES --> WhiteBox --> CentOS 3.1 --> CentOS 3.3 --> CentOS 3.4. That machine reported RH, WB, and c0 packages before it get whipped out to test Fresh 3.4 installs.
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