From our server team:

A number of serious security vulnerabilities affecting multiple CPU architectures were recently disclosed by Google’s Project Zero team as outlined in our support annoucement on Jan 4. In order to address the disclosed vulnerabilities, the physical hardware on which your website resides will need to undergo maintenance. This maintenance specifically patches the Meltdown vulnerability; the Spectre vulnerability will be addressed in a future maintenance cycle. We will inform you of these maintenance cycles via additional communications.

The maintence begins at:
Jan 13th 2018 – 11:00PM EST

During the maintenance window, will be cleanly shut down and will be unavailable while we perform the updates. A two-hour window is allocated, however the actual downtime should be much less. After the maintenance has concluded, the server will be brought back online.

We regret the short notice and the downtime required for this maintenance. However, due to the severity of these vulnerabilities, we have no choice but to take swift and immediate action to ensure the safety and security of our customers. For these reasons, we must adhere to a strict timetable, and will not be able to reschedule or defer this maintenance.

They will have it up shortly.

Ah, the joys of high-reliability computing…