What Amazon left out, and what El Reg didn't mention in their article 12 hours ago, is Availability Zones. You're not supposed to have to go multi-region in order to be able to sustain a major AWS outage. Being in multiple AZs is supposed to allow you to survive a fat finger by an AWS employee.
The fact that Amazon's statement talks so casually about US-EAST-1 S3 makes it clear that there is no segmentation of S3 between AZs. If S3 isn't segmented that probably means other AWS services aren't either. Paid extra for multi-AZ RDS? Added extra EC2 instances for multi-AZ load balancing? It won't help at all if RDS and ELB are administered at the regional level anyway.
I think Amazon has some splaining to do. If their own services aren't redundant across AZs then what is the point of customers paying extra to be in multiple AZs? Is the only independent component of AZs the power source? That is a far cry from Amazon's selling points of multiple AZs.