We can all learn from problems. The Google App Engine team has created a teachable moment through a remarkably honest and forthcoming post-mortem for February 24th, 2010 outage post, chronicling in elaborate detail a power outage that took down Google App Engine for a few hours.
The world is ending! The cloud is unreliable! Jump ship! Not. This is not evidence that the cloud is a beautiful, powerful and unsinkable ship that goes down on its maiden voyage. Stuff happens, no matter how well you prepare. If you think private datacenters don't go down, well, then I have some rearangeable deck chairs to sell you. The goal is to keep improving and minimizing those failure windows. From that perspective there is a lot to learn from the problems the Google App Engine team encountered and how they plan to fix them.
Please read the article for all the juicy details, but here's what struck me as key: