How about....
An application for P2P storage of all wallet files, such that you set yours for upload, and it is automatically downloaded by all other P2P users. Of course, wallet files would be truecrypted.
Unless a way is found to break truecrypt encryption, then the wallets are very safe from accidental destruction, and very secure from those that would do harm with backups.
You are talking about p2p encrypted backup system
Wuala! (128 bit AES and 2048 bit RSA and SHA-256 and bla bla bla) - go and get it. It even more secure as nobody will guess that your wallet is stored in clouds with all other encrypted gargbage of the world.