Appfog Takes On Amazon Lock-In With OpenStack (opens in new tab)

Actually, the programmatic ability to spawn EC2 hosts is great in-the-small, for testing - you want to do an upgrade right? Spin up a fresh instance (or five), do your chef/puppet scripted deploy, load balance five percent of your users to the new one... watch for problems, don't see any? crank up the knob... once you're 100% on the new one, hold on to your rollback option for a bit, once you are confident in the new one - poof turn off the old one. Depending on how often you do releases, you can have an awesome safety net for maybe 10% more than your baseline instance cost... get a new developer? "here, run this script, now you have your own copy of the product to screw around with - when you get something working, push your changes"... basically there's a lot more value to that automation than just autoscaling.

Some people are using EC2 far beyond 'hosting a website'. If you're leveraging the EC2 interface to stop and start instances on demand (say, to power per-user instances for an application) then you're 'locked in'.

DynamoDB could be equated to Mongo or Redis, but it isn't either one of those exactly, so the switching cost is slightly higher than if it were.

SES is basically there to replace standard SMTP, but it isn't standard SMTP, so the switching cost just went up a little more.

Beanstalk is (as I understand it, could be way off here) similar to Glassfish or Weblogic (for Java), but again, isn't quite, so your switching costs go up again.

Etc., etc.

I don't necessarily disagree that lockin doesn't just happen, you get there by choosing to leverage non-standard components, vs. standing up another instance and running Mongo or SMTP, etc., but it's hard to make the decision not to leverage those things when they're there, available, and look and feel similar to the tools you need, but aren't.