RDS recently added cross region snapshot copies, and more importantly, cross region replication for at least MySQL. Those were the last two features I was waiting for to jump to RDS. In fact, I was in the process of setting up cross region backups using just the cross region snapshot copy when they released the new cross region read replicas feature.

I'm very much looking forward to moving our manually managed cross data center MySQL replication/admin to RDS. But I also don't have to scale MySQL to ridiculous levels either, I just need very high availability.