No, not chicken butt.
They ship with 2 drives, but raid is not enabled out of the box.
So, if someone else sets it up for you, you might need to go back and enable the raid.
Here is how: http://www.copiouscom.com/2011/03/how-to-raid-mac-mini-server-without-reinstalling/
Another train of thought: http://blog.scottlowe.org/2010/07/17/enabling-raid-1-on-a-mac-mini-server/