It seems this service is targeted towards specific applications where write traffic is somewhat independent between 2 regions. However, you can shoot yourself in foot, if 2 regions are trying to update the same row, because of eventual consistency.
>> You can now create tables that are automatically replicated across two or more AWS Regions, with full support for multi-master writes, with a couple of clicks. <<<p>Hamm, If I understand it correctly, REGIONS are no longer heavily isolated.