I believe that our biggest challenge of moving to a vendor run cloud is different and less frequently addressed than the topics covered in the initial posting.
The biggest impact of losing a cloud vendor (or for that matter a hosting vendor) on which you run large, critical operations is on business continuity*. The promise of using hosted services/hosted platforms/cloud is that you can save big on people, energy, software, hardware…. Once we laid ‘em off and turned ‘em off we might be in a bit of a pickle to adapt and move our processes and applications to a new vendor– even with some warning of a bankruptcy or significant change in architecture, applications, or offerings. We need to plan for the effort and resources required to ensure business continuity and be able to decide when we need to act. We need to monitor and communicate with our vendor to ensure we get a heads-up to that which will impact us, be prepared to assess the risk and, if necessary, find a solution. This isn’t a one-time thing—it’s a continuing process based on situational awareness, risk, impact, and cost.