What are all of Amazon's web services and what do they do?
quora.com
quora.com
If it took a year to build your service on AWS products, it shouldn't take years to do it again with another provider now that you've done it before. A server is a server, whatever you've programmed to run on those virtual servers will run on identical virtual servers at another company. It's only the parts of your system that interact with Amazon's APIs, and your human systems/policies, that have to be reworked.
And if you're big enough that your systems take years to build, you have a disaster plan already. If Amazon blinked out of existence tomorrow, Netflix wouldn't be standing there with no idea what they'd do to get back online.
On second thought, I guess there would be a short term huge increase of sales on eBay, where most Amazon sellers also sell, so I guess "out of business" is hyperbole.
What's a shame is that right now there isn't a web-based GUI for this service yet, and the boto Python module's IAM support is currently undocumented, but at least the code is there. A bit of code reading to get it up and running.