Another risk consideration is that anyone getting unauthorized access to your AWS account can delete all your resources and all your backups (snapshots, etc), effectively putting you out of business. [1]
One solution is to backup to a separate backup-only AWS account, with super-serious access controls (MFA and password physically locked away somewhere). Set up a "write-only" link, such that backups can be added, but never removed. This way, in the worst case, your runtime infrastructure can be decimated, but your data backups would be safe.
I prefer this method. Having multipe aws dashboards sounds like a nightmare. I would rather use the backup account approach with MFA tied to the administrator accounts on each aws site.
Multiple AWS dashboards is actually really easy with multiple Chrome profiles (not that I go to them often, there are APIs for a reason) and tends to encourage much better, much more isolated application design. I've worked in environments with a single account and in environments with multiple accounts and I can't imagine going backwards.
One solution is to backup to a separate backup-only AWS account, with super-serious access controls (MFA and password physically locked away somewhere). Set up a "write-only" link, such that backups can be added, but never removed. This way, in the worst case, your runtime infrastructure can be decimated, but your data backups would be safe.
1 - http://arstechnica.com/security/2014/06/aws-console-breach-l...