A passing thought:
Would it be fair to compare Google’s App Engine to Ford’s assembly line, in a roundabout sort of way? Ford’s mass produced cars put cars within reach of many more people, and over time, put paid to the many custom car producers who didn’t adapt. Google’s App Engine is a way for people to easily scale their web applications in a way that wasn’t possible until now. No fiddling with EC2 images, or hosting, or a bunch of other stuff that, for the time being will still drive people to want to control their own infrastructure, but the prospect of very cheap hosting and very easy scaling is potentially something that will change things significantly.