ok, i'm getting it
but if it is that way the client software really need a lot of work before can be widely used
i guess value of coins itself will be enough to force creation of proper backup solutions soon
i guess my first one will be encoding wallet.dat to base64 and printing it on laser printer
(just 25 pages of text) with copy on dvd-ram
i understand that as long as wallet.dat keys matches whatever stored in this cloud
it will be valid ie. no expiration in any way
start simple - have more wallets (daily for pocket change and small amounts; occasional use wallet for savings)
they would require different backup approaches. and you would value them differently
keep a list of vanilla addresses somewhere where you could dump your coins if in hurry & need of securing your coins
(emergency withdrawal from a web service ewallet p.ex.)
aim big - generate brazillions of key pairs and see if you find keys from lost money (or guess someone's wallet address that's funded)
of course you never know if you find lost money or just guessed someones wallet key pair (if you'll be that lucky, you might try gambling as well