That FAQ you yourself pointed to doesn't mention that there are common components.
We now know that when Amazon said - in that very FAQ - "even extremely uncommon disasters such as fires, tornados or flooding would only affect a single Availability Zone" they were very carefully not lying, but implying something that simply isn't true. We didn't know 18 months ago that multiple AZs would fail simultaneously (unless there was e.g. a huge earthquake). I agree that we know that now.
You believe we won't wake up at 3AM one morning to learn of an unanticipated way that multiple regions will fail at the same time. I don't share your faith.
Edit: This in reply to joeyi's comment above. It got double-posted, and I replied to one of the copies at the same time as joeyi deleted it!
I share your paranoia in general (as ops), but can assure you that regions are very isolated from one and other. I know that releases are rolled out on a very long schedule (think quarter long release), and that is to prevent what you describe.
I would argue that the application (ie: the application being hosted on AWS) probably is going to fail before multiple regions do simultaneously and that should be addressed, before thinking about going multi-provider.
Do you work for AWS as well? If so, I'd ask that team AWS spend less time astro-turfing on HN, and more time documenting your systems, so we can assess these risks for ourselves.
For example, I haven't heard of any precautions taken against a thundering herd of clients retrying requests in other regions if us-east goes down. What does AWS have there? How much spare capacity do you run in each region?
We now know that when Amazon said - in that very FAQ - "even extremely uncommon disasters such as fires, tornados or flooding would only affect a single Availability Zone" they were very carefully not lying, but implying something that simply isn't true. We didn't know 18 months ago that multiple AZs would fail simultaneously (unless there was e.g. a huge earthquake). I agree that we know that now.
You believe we won't wake up at 3AM one morning to learn of an unanticipated way that multiple regions will fail at the same time. I don't share your faith.
Edit: This in reply to joeyi's comment above. It got double-posted, and I replied to one of the copies at the same time as joeyi deleted it!