I think an important lesson from the UniSuper thing is that, while your cloud provider may work very hard to avoid single points of failure in their systems, your _account_ with them can also be a single point of failure.

To put it another way, major businesses historically had to war-game the scenario "your primary data centre just ceased to exist". Moving to the cloud doesn't stop you doing that, it just replaces "primary data centre" with "primary cloud provider account".