According to https://status.aws.amazon.com/ there were route53 issues this morning, however the issues were not supposed to impact queries to existing DNS records.
For us, we saw non-DNS-related connectivity issues this AM where route53 worked correctly, requests were able to reach the ELB, but then were never received by our EC2 instances. The timeframe of our issues matches that of the reported route53 issue.
Anybody else run into this sort of intermittent connectivity issue this AM?