We need to do essential maintainance on the main MusicBrainz database server today (specifically upgrading to Ubuntu 12.04 LTS). We’re aiming to get this work completed within an hour, and will require MusicBrainz to be in read-only mode for the duration of the upgrade. We’re going to go read-only from 2PM UTC (6AM PST, 9AM EST, 3PM CEST) to begin this work.
Sorry for the inconvenience!
MetaBrainz Blog 