WordPress.com was down from about 7am - 9am UTC, Sunday, August 8th.
One of our three major datacenters was taken offline for scheduled emergency maintenance. Shortly thereafter, a second datacenter went down because of hardware failure in a core piece of infrastructure. With two out of three datacenters offline, WordPress.com couldn't function.
We're still experiencing intermittent problems as we continue to recover from this simultaneous outage, but most things should be working.
Naturally, no one cares more about your content than you, but we're a very close second. We apologize for the downtime and are working hard to clean up any leftover problems.