I think there are some good cloud backup service providers out there, yes data loss is an issue and thats why a lot of IT firms create their own private clouds, but even they are begining to look into Azure and Adobe to host some of the 'lower risk' apps. I believe you need to a co-existence of both public and private clouds, that way you can choose what data goes where, and accept the risks of the public cloud.
Theres an interesting site for new comers to cloud based services here: www.backuptoclouduk.co.uk if anyone wants get a good grounding on what this cloud business is all about