UPDATE: From status:
Since approximately 4:00 pm Pacific Daylight Time, Six Apart has been the victim of a sophisticated distributed denial of service attack. This has affected all of Six Apart's sites, causing intermittent and limited availability for TypePad, LiveJournal, sixapart.com, movabletype.org and movabletype.com. Our network operations staff is working around the clock with our Internet access providers to resolve the issue. We appreciate your patience and support, and will provide updates as we have them.