Or be forced to give up access statistics via Pen Register.
Or provide governments the ability to access your data via CALEA compliance hardware/processes.
I value the privacy of my data as much as I value the integrity of it. I don't see myself doing much cloud computing in the near future.
Keeping your personal data on a free account might be a bit of a crapshoot, but keeping your company data on a paid for service account shouldn't be.
http://www.kde.org/whatiskde/kdefreeqtfoundation.php
I think that's a difficult problem for software-as-a-service to overcome.
Basically what you're talking about is standards - but I think the SaaS/Cloud space is too immature to be able to define standards at this stage... In fact, whilst it would give consumers extra security, it would very likely slow down innovation.
Issues of software freedom aside, I think the key to making people trust the cloud is to make the data contained in the services more transitive. Essentially, creating a standard Import/Export for the web. i.e. - If I decide to switch to vimeo for my web video needs, I'd like to be able to import all of my videos from youtube without much fuss (or make a local backup). That's not a great example, but it's the general idea.
Hmmm...after I think about it, this pretty much boils down to: "let me get at my data in a format that I can read."