Are you doing the switch now or are you upgrading CentOS after an already good switch?
I switch sometime ago. With no Problems until this problem with rpm now.
Here is a link with specific info: http://www.centos.org/modules/smartfaq/faq.php?faqid=19
I switch following this instruction.
Now I have this: :-(
# rpm -qa | grep -i rpm- rpm-python-4.2.3-21_nonptl rpm-libs-4.2.3-13.WB2 rpm-python-4.2.3-13.WB2 rpm-4.2.3-21_nonptl rpm-4.2.3-13.WB2 rpm-libs-4.2.3-21_nonptl