Software pioneer Dave Winer knows about disruptive technology. He was instrumental in formulating RSS, XML-RPC, OPML, outliners, and podcasting.
Now, what Google announced is really exciting! I'm not kidding. It's even better than I hoped. Yes, it's only Python, but IBM's PC-DOS was only BASIC and Pascal when it first came out, and it didn't matter. Yeah, I preferred C, but I coded in Pascal because that's what you had to do to get an app running. What you're going to see here that you've never seen before is shrinkwrap net apps that scale that can be deployed by civillians. That's a mouthful, but that's what's coming. Why? Because here is a standardized platform that can be stamped out in the billions of units. Maybe Google can't do it, but the perception is that they can. Who is willing to stand up and say Google hasn't nailed scaling? What PCs did in the 80s, Google is doing now. PCs took the black magic out of owning a computer. Now Google is taking the black magic out of operating a scalable web app. Python is the new BASIC.
The point is, Google App Engine may be neither competitive nor monopolistic - it might just be trivial as Google Pages or Google Base. So far it seems pretty simple and useful, though. We'll have to take a deep breath, hope that Amazon and others step up their offerings a notch or two in response, and see what the future brings.
Clint Ecker of Ars Technica also notes a potential downside in Google's App Engine:
Perhaps the most blatant downside is being locked into Google's platform. Existing projects will have to be ported or written from scratch, and those that rely on traditional relational databases will probably have difficulty making the transition. Even more difficult would be transitioning your application to your own servers if you choose to leave Google's tender embrace. Once you've created an established application on top of Google's authentication service and stored all your data within the company's datastore, removing all this code and data and moving it to another location would appear to a be fairly onerous task.
It's still early in the platform-as-a-service sweepstakes. But the signs are clear. As Nick Carr pointed out in his book The Big Switch, the large clouds will cover the planet with computing infrastructure. Amazon has to be more motivated to improve its Elastic Compute Cloud, and big players like Sun, IBM, Oracle, Microsoft, Yahoo, and others will also be inspired to open their clouds to developers. But as Dave pointed out, we are in the BASIC, embryonic days of platforms-as-a-service.