When we were looking to get off of a shared hosting server, our hosting company suggested we go join their cloud system. This came with promises of easy scalability (not something we're too bothered with at the moment) and, most importantly for me, a claimed 100% redundancy on hardware which, I was told, meant zero downtime should something fail.
That is unless it's a primary component - a raid array or some such - that meant our site was offline for almost 3 days while theirs and Dell's engineers tried to figure out what to do. Needless to say, we were not impressed.
We now have our own managed physical server, regularly backed up, great support and a guaranteed 1 hour hardware replacement. This means that should the server fail, we should be up and running in a matter of hours rather than days.
Cloud computing is just that... a fluffy cloud of no substance. But that's just my experience.