My dashboard says "Degraded EBS performance in a single Availability Zone". It then lists each of the five zones as "Availability zone is operating normally." http://cl.ly/image/202F3B0I371g
I was seeing that too, but it looks like Amazon has now updated the availability zone status. When I run ec2-describe-availability-zones from the command line, it's telling me that us-east-1b is impaired. (Availability zone mapping is different for each account, so my 1b may be some other availability zone for you.)
