It appears that Amazon is introducing a new service specifically targeted at Relational Databases helpful hints. You can choose from MySQL, Oracle, and Microsoft Sql Server.

Amazon Relational Database Service (Amazon RDS) is a web service that makes it easy to set up, operate, and scale a relational database in the cloud. It provides cost-efficient and resizable capacity while managing time-consuming database administration tasks, freeing you up to focus on your applications and business.