From: P J pauljflists@gmail.com
I've read that it's not recommended to automatically apply updates via yum-updated on production servers, but I keep encountering servers that have this enabled.
Some parameters/configurations/functionalities might change/appear/disappear, depending on the type of development (some projects are stable and other projects just do not care about backward compatibility). If you do manual updates, you will notice that some configuration files may change in the process (see the .rpmnew and .rpmsave)... If your server is critical, you'd better test the updates on a non critical server before.
JD