We will have a scheduled maintenance window tonight from 7:00pm to 11:00pm PST. The following changes will take place:

7:00pm PST (0300 UTC) OSPF change. We’ll be deploying a configuration change on how the default route from BGP speaking routers is injected into OSPF. See bug 466111 for more detail. No downtime [...]

We will have a scheduled maintenance window starting tonight at 7:00pm PST. The following changes will take place:

7:00pm PDT (0300 UTC) crash-stats.mozilla.com (Socorro) database maintenance. We’ll be partitioning the production Socorro database (refer to bug 475815 for details). During this time, crash-stats.mozilla.com will be offline. crash-reports.mozilla.com will be up and accept crashes. [...]

We will have a scheduled maintenance window tonight from 7:00pm to 11:00pm PST. The following changes will take place:

7:00pm PST (0300 UTC) addons.mozilla.org updates. We’ll be updating addons.mozilla.org to pick up code updates (bug 475774). No downtime expected.
7:00pm PDT (0300 UTC) ) crash-stats.mozilla.com (Socorro) database maintenance. We’ll be partitioning the production Socorro database (refer to [...]

We will have a scheduled maintenance window Thursday night from 7:00pm – 11:00pm PST (0300 – 0700 UTC). The following changes will take place:

7:00pm – We will be replacing a faulty midplane on a blade chassis containing 14 servers which support the following services:  addons.mozilla.org, download.mozilla.org, crash-stats.mozilla.com.  With the exception of crash-stats, the affected servers [...]

We will have a scheduled maintenance window tonight from 7:00pm to 12:00pm PST.  The following changes will take place:

9:00pm PST (0500 UTC) addons.mozilla.org/Zeus ZXTM performance testing. We will be running a performance test of addons.mozilla.org behind a Zeus ZXTM cluster. See bug 467502 for more information (and this blog post).  No downtime is expected, [...]

We will have a scheduled maintenance window tonight from 10:00pm to 12:00pm PST. The following changes will take place:

10:00pm PST (0600 UTC) border1 Sup720-3BXL upgrade. See http://blog.mozilla.com/mrz/ for more details (this is the second half of Tuesday’s upgrade). During this time all all BGP sessions on border1 will be shutdown and [...]

We will have a scheduled maintenance window tonight from 7:00pm to 11:00pm PST. This is being tracked in master bug 464743. The following changes will take place:

7:00pm PST (0300 UTC) support.mozilla.com updates. We’ll be updating support.mozilla.com to pick up code updates. No downtime is expected.
7:00pm PST (0300 UTC) Root-level DNS changes.  We will [...]

(Apologies for the short notice.  We generally want to stick to our normal advertised maintenance windows but sometimes technology works against us.)
We will have an emergency maintenance window tonight from 6pm to 11:00pm PST.
The following work will take place:

6:00pm PST (0200 UTC) ) EqualLogic storage array firmware upgrade.  See bug 464458 for details.  We’ll [...]