After moving from ensim to cpanel, I'm noticing that I have no domains listed in netstat other than the initial domain for my box.

Sites that are on their own IP are not showing up by domain name, they are showing up ev1s-XX-XX-XXX-XXX.ev1:http

I pressume that this problem is due to my incompetance, what is it that I've forgot to do?

That is the reverse dns of the ip that you are seeing. Login to the members section and setup the PTR record for each ip address to whatever that domain is. It will take a few hours for it to get into the system but once it is done that will be updated.