Actually posted a community outreach poll to get some information about this.

As with any backup, you would perform it while you still retain access to the key. However, you can never regenerate the private keys for a specific user (or the blockchain wouldn't be a cryptographically secure ledger).

To get some kind of "backup", I have been considering writing a program that will allow you to download all of a user's (your) blogs and repost them as a new user (your new account).

If you are concerned with getting your STEEM back... the ONLY way is to backup your private keys. There is nothing any service can do to return your STEEM to you that is in another wallet.

Might be a novel idea to be able to make a blockchain (a bit) less secure by allowing the private key to be downloaded with device proof. Essentially 2FA. The more ways you create to manage, backup, download private keys, the larger the attack surface becomes.