Last night at about 6:30 pm (Tom Warren of Neowin comments the actual downtime was between 6:24 and 7:10), after “a configuration change during some internal testing”, Bing was either unavailable or returned incomplete results.  According to the Bing Blog:

As soon as the issue was detected, the change was rolled back, which caused the site to return to normal behavior. Unfortunately the detection and rollback took about half an hour, and during that time users were unable to use bing.com.

Larry Dignan over at ZDNet seems to think that it’s a happy day at Bing, because the tech press actually noticed the downtime:

Microsoft should be happy that some folks noticed Bing tripped. Back in the day, Live Search could have disappeared for a week before anyone noticed.

Anyway all is back to normal, they’re “running a post mortem to find out how our software and processes need to be improved”, and chanting the phrase “all PR is good PR!”