Everyone that plays Demigod online is aware that there is currently an outage on the Demigod MP servers (anytime you host a game, you get the Nat Facilitator error). The issue began on 8/3/2011 around 2AM EST and is still ongoing as of 12:50PM EST.
I've chatted up a few people at SD (and sent the appropriate emails to support) and they are aware of the issue. The issue appears to be because many of the servers that were once housed at Stardock are being moved to Gamestop facilities. The closest thing I've got to an estimate on how long it will take to get things back up and running is "hours yet, maybe a day." So, they are working to resolve this. I'd just check back in from time to time and see if things are back up and running.
Update 8/3/2011 from Island Dog: "Just an FYI that it won't be back tonight, they are looking at sometime tomorrow."
Update 8/4/2011 from T-man: "We are still working on getting the NAT Faciliator back online. But due to several technical difficulties it is unlikely that we will get it back online this week. I would estimate that we will have it working again mid next week. Our apologies for the inconvenience."
Update 8/15/2011 around 3PM EST: The servers appear to be back up and the issues seem to have been resolved.