I saw Amazon introduced new Amazon Aurora MySQL migration from native MySQL to Amazon Aurora MySQL.
Would it be possible to migrate back from Amazon Aurora to regular MySQL with Amazon RDS?
Amazon’s Aurora is MySQL wire compatible so you can always use tools such as mysqldump to get your data back out into a form that you could use to import back into a regular MySQL instance running in RDS, an EC2 instance or anywhere else for that matter.
Since posting this answer Amazon has also released the Database Migration Service which can be used to do zero downtime migrations between MySQL -> Aurora MySQL (Aurora also now supports PostgreSQL) and back. It also supports heterogeneous migrations such as from Oracle to Aurora MySQL or a number of other sources and targets.