I didn't realize it was per server since everytime I dabble at the create a new character it asks me which server to I want to choose I think. I may be wrong on that. I just thought it was 12 toons total. I know it went up to 12 with this last merger for people who had several toons on different servers.
At least I think thats what I read.
Feel Free To Disagree.....Most People Do Anyways