Google launched their app engine today, and I'd like to be the 10,000,000th pundit to comment on it. First, it's clearly a nod to Amazon's thing, a direct competitor for developers looking to host projects on proper servers without incurring proper hardware costs.
Everyone else is already describing what this is, but I'm interested in the ethical and motivational implications. Most of what I'm reading about the GAE is some variation of "joy, now I have to learn Python", which I think is an accurate stand-in for Google's entire stance on this project. A quick initial read of their documentation suggests that there's a lot more than "learn Python" here - there's also "learn Django" and "learn BigTable". GAE is as much an architectural, moral, and stylistic project as it is a technical one. Where Amazon gives you shiny rack of tools to play with, Google gives you the Tao.
At the moment, Google seems to have tuned their project towards the world of web applications, not the kind of general purpose computing offered by Amazon. I expect this to change. AWS is pushing a menu of services like SQS that provide specific pieces of a distributed infrastructure. GAE is giving you the whole shooting match in one go, but telling you approximately how it should be used. I've heard a bunch of conjectures on why this is: some people think it's a way to smooth the entry path for startups looking to get bought by Google ("hey, we already use all your stuff"), while Tom sneakily suggests it's a golden parachute for soon-to-be vested ex-employees who'd still like a bit of the old infrastructure to play with.
My own initial take on both projects has been like night and day. Amazon's services were like a breath of fresh air while so far, Google's has filled me a dread I dare not name, in spite of proudly using Python as my "thinking language" of choice. AWS exists happily as a component set for other applications, and I use S3 extensively to serve map tiles and listen to music while Crimespotting runs on EC2. I think that in this case, Google is commoditizing the wrong end of the stack. They seem to be providing the equivalent of single-language shared hosting without really opening up the benefits of a massive computing infrastructure that a tiny minority of applications need or want. I take my own initial preemptive exhaustion as a sign that they are expecting too much of their prospective users. Kiss the ring.
That said, both of these services have an ethical dimension that I appreciate. I trust that machine instances and running applications not seeing a lot of activity are swapped out in favor of those that are, a form of carbon footprint minimization impossible to achieve with your billed-monthly colocated server. In this case, scale does matter as long as the two companies keep their prying eyes out of the data and processes entrusted to them. I'm looking forward to seeing greater commoditization in this area, and I happen to think that Amazon is doing a significantly better job moving us in that direction.