Yeah, I know. This happened last year, too, though I forget why the downtime happened. A few of us suspect it has to do with the blizzard that recently hit the northeast, at least to a certain degree. Other sites have been affected.
On a side note, there is a rogue twitter account, which isn't affiliated with RHDN in the slightest, stating that Nightcrawler shut the site down. Do not believe this. RHDN does not have any twitter account, official or unofficial.
Hopefully the downtime is resolved shortly.