I have been working on the script some lately, and I cleaned it up a whole lot to make it easier. I have gotten all of the prompts out at this time besides the ones where you have to manually enter common names.
I have also added Mailman support. It should be good to go. Please test it out.
Does anyone want to help me add CentOS support? I am not very familiar with it, and there are some things that appear to be much different.