We'll be upgrading some networking equipment on December 22 between 2:00 and 6:00 AM EST.  You might see some delays and brief outages during that maintenance window.

UPDATE: 2010/12/22: 6:30AM: Most equipment has been upgraded without any downtime.  The job ended up getting split into two pieces, so there will be another maintenance window on 12/24 as well.

UPDATE: 2010/12/24: 7:00AM: All devices have been upgraded.  We had a couple minutes of downtime around 4:00AM.  For those of you who were awake at that time to notice, our sympathies...  :)