I received quite a few emails and voicemails advising me that the HDW site was down last night/early this morning. Of course, being on the west coast, all of this took place (and the site was back up) by the time I awoke this morning.
Ron Tiller at HDW was kind enough to provide the following explanation:
"Shortly after 1:00am eastern time, our entire network went down due to a failed power supply (with a brand new battery no less!). Although the web server itself was happily running, every network device in the office was out of commission, making the web server inaccessible. We got the network back up and running around 9:00am eastern time Sunday morning."