[Edit: this is to expand on Tony's post. He types way faster than me, and by the time I submitted this, he had already posted LOL]
Just for clarification for those that don't know. What you use to deliver content on your site (ie, WordPress, Joomla, Drupal, static pages, 100% custom program) has nothing to do with what happened today.
When you tell your browser to go to a domain, say, http://www.lawnsite.com
, your computer looks up the on NameServers what is the IP address of the server it should ask for the URL you gave. (in my example, for lawnsite, 22.214.171.124)
The problem today was that people could not access NameServers at GoDaddy. So your browser (and/or mail client) would complain it couldn't find the server. If you have your domain set to use GoDaddy's nameservers (most people that don't know better, when they register a domain with godaddy, leave it that way), then it doesn't matter one bit about your site at all, because no-one even GETS to your site.
Think of it this way. Back when you only used phone books to look up a phone number. You want to call Joe Schmoe. You need to know his number, but the phone books for his city isn't available. It don't matter what language Joe Schmoe speaks, you never even able call him.