David, absolutely. But that is true whether you are talking about something on the cloud or something under the desk in front of you. The sad truth is that most people do neither. And I'm speaking as someone who hasn't got time machine working on my new laptop yet as well...

But the need for backup is independent of the storage site I think. And good institutional systems are required to enforce (or if you prefer facilitate) good backup systems. It is one area where the institutional repository should be playing a strong role (as Dorothea pointed out on Friendfeed, the people in charge of such things are uniquely placed to deliver on this as well). For actual day to day usage my feeling is that discipline based or departmental repositories will be more responsive to user demands - but at the end of the day the function of backstop storage should be handled by the legal entity responsible for agreeing the funding arrangements.