[CentOS] Upgrading with Centos

Hello,

I work with a public school system in VA. Currently we run Fedora on all
our servers. We have just tried an upgrade with CentOS on an old print
server with success. We have a have a few samba servers that run winbind
and an email server that is running postfix+squirrelmail+spamassn+anitiv.
Has anyone tried doing this with success?
-- 
Bo Lynch
Systems Administrator
RedHat Academy Instructor
Energy Manager
Amelia County Public Schools