8:10 AM PDT Some customers have reported intermittent resolution issues with .io domains. We can confirm that Route 53 DNS services are operating normally at this time and these issues seem to be related to the .io top-level domain provider.

8:43 AM PDT We can confirm that resolution of .io domain names are intermittently failing due to issues with the .io TLD name servers that are hosted external to AWS. Route 53 name servers continue to operate normally, but customers who have sub-domains of .io hosted on Route 53 may experience issues until the .io TLD name servers hosted externally are resolved.

Anyone have any other info?