<blockquote>Currently, there's no way for a cloud storage service provider to directly migrate customer data to another provider. If a service goes down, the hosting company must return the data to its customer, who then must find another provider or revert back to storing it locally, according to Arun Taneja, principal analyst at The Taneja Group.</blockquote>
via <a href="http://www.computerworld.com/s/article/9216159/What_happens_to_data_when_your_cloud_provider_evaporates_">What happens to data when your cloud provider evaporates? - Computerworld</a>.

This is only a problem if you don't have a physical backup of your own data somewhere under your control.  Expecting the cloud to be the end all be all for all IT needs is a mistake IMHO.  Don't put all your eggs in one basket.  The cloud does serve useful purposes.