Red Hat should lighten up
When I learned that Red Hat Enterprise Linux 5, which is a big release for Red Hat I've been looking forward to for some time, was coming out on March 14, one of the first thoughts that crossed my mind was, "Great—when's CentOS 5 coming out?"
Even though Red Hat has always been very nice about providing us with entitlements to test its products, entitlements are a major pain to mess with. Sometimes our entitlements expire, and I have to head over to the Red Hat Network to unentitle some machines in order to entitle others. Frankly, from our perspective as a testing organization and as a group of people who often build up and tear down systems in different combinations, RHEL is actually more of a pain to work with than Windows, for which there were (until Vista, at least) volume license copies that we could use flexibly and without expiration.
Even better are free Linux distributions, which you can get in all sorts of forms and from all sorts of locations. Debian is my favorite example of deployment flexibility.