Well it's interesting that today I had a panel on a web site not unrelated to accounting. The question spanned whether I'd trust an on-line service with company accounting data (in two question forms) or whether no-way-Jose, I'll keep my data in house under all circumstances.
At least at the time where I said (admitted? confessed?) I'd trust the data to the cloud, I was most interested in the results so far, that suggested that about a third would not trust their data outside their organisation.
I could feel the religious zeal.
What is interesting is that their concern, and the reason why they are so sure, is completely for the same reason I would trust data, not to a cloud, but to a known, proven and trusted (read secure) hosted service. In my experience the security implemented, the performance and the service terms from professional hosters (and yes you need to visit and eyeball them) are usually more reliable than the procedures and management of in-house solutions - even when you believe this is not so.
For business protection I believe this constitutes a better solution. If you're unsure of course the middle way of keeping your own backups as well as relying on the hosted service and its backups provides additional insurance.
So in summary I'd recommend a real review of the protection of your business data, with a dispassionate review of the risks involved. With security it is usually the internal processes that prove to be the "weakest link". Unfortuately this is usually found too late.
Full disclosure - I work in hosting for Perceptive Online, so I know and trust the safety, security, and rigorous procedures involved in Perceptive Online's hosting, and have the highest expectations of any other hosting or in-house server management. We have also just completed the ICAEW Hosted Service Review and I believe we're the first Hosting company to have been through this process.