On Why I Don't Like Auto-Scaling in the Cloud - O'Reilly Broadcast
http://broadcast.oreilly.com/2008/12/why-i-dont-like-cloud-auto-scaling.html

Dynamic scaling is better than auto scaling in the cloud - George Resse

Good rant about why auto-scaling is not dynamic scaling: two of the most widely cited advantages of the cloud. Not entirely convinced by the argument, though. I suspect governors can be used to manage scaling in a sensible way.

Sometimes traffic is truly unexpected. But not as often as you think. If you know you are getting coverage in some publication, marketing should have done an ROI projection on the campaign and be able to provide you with expected response rates. But you don't want it to auto-scale. Auto-scaling cannot differentiate between valid traffic and non-sense. You can. If your environment is experiencing a sudden, unexpected spike in activity, the appropriate approach is to have minimal auto-scaling with governors in place, receive a notification from your cloud infrastructure management tools, then determinate what the best way to respond is going forward. Here, the auto-scaling is simply a band-aid to enable a human to use dynamic scaling to define an appropriate, temporary capacity to support the unexpected change in demand. If you know you have a batch window from midnight to 3am, set your cloud infrastructure management tools to add capacity at 11:30 and throttle back at 3:30.

Makes good sense. I'd probably disagree on a few points if the cloud is owned/controlled by one's own organization.