Also, while I'd love to be able to tell you this was due to some catastrophic error and not a preventable problem, unfortunately this next round of downtime is the result of human error (mine). You have my (and our) sincerest apologies and assurances that we really do take this downtime seriously and we're doing everything we can to put measures place to keep downtime like this as rare as possible.
If you're interested in finding out about the work we're doing to help prevent long downtimes please follow
news and 
lj_backend, where we post fairly regularly about new hardware and network infrastructure changes.