Four days after Steve Jobs’ keynote address at Apple’s (AAPL) Worldwide Developers Conference, commentators were still searching for ways to convey what it signified — often by comparing Apple’s approach to Google’s (GOOG) or Microsoft’s (MSFT) or Amazon’s (AMZN).

Below, we’ve posted excerpts from the best analysis we’ve seen or heard this week. If you come across something that helps you understand what Apple is trying to do, put a pointer in the comment stream and maybe we’ll add it to the mix.

The Brooks Review’s Ben Brooks in Apple’s Magnum Opus:

What Apple has done here is to sit down and say: “what bugs me and ideally how should it work”, then they turned that into WWDC’s announcement. These changes don’t feel like bug fixes or feature upgrades, they feel like a rethinking of computing.

Daring Fireball’s John Gruber in “Demoted“:

The key line was when Steve Jobs, describing iCloud replacing iTunes as your digital hub, said, “We’re going to demote the PC and the Mac to just be a device.” … This is a fundamentally different vision for the coming decade than Google’s. In both cases, your data is in the cloud, and you can access it from anywhere with a network connection. But Google’s vision is about software you run in a web browser. Apple’s is about native apps you run on devices. Apple is as committed to native apps — on the desktop, tablet, and handheld — as it has ever been. Google’s frame is the browser window. Apple’s frame is the screen. That’s what we’ll remember about today’s keynote ten years from now.

Wired’s Steven Levy in Jobs to PC: ‘Your Busted!’:

Jobs himself took pains to underline the significance of iCloud in the ascension of the new, pad-and-phone-oriented post-PC paradigm. iCloud, he said, marks the completion of a long quest to liberate the computer from local files and all the desktop mishigas involved… Google’s cloud embrace is still more radical than Apple’s. As of now, Apple regards the cloud as a hub; Google’s Chrome OS treats the cloud as the computer itself… By comparison, Apple’s cloud is timid: It’s about storage and synching as opposed to a streaming, real-time, extension to your actual machine. At Apple, the action is not on the web, but in the apps.

Techcrunch’s MG Siegler in “It Just Works”:

Apple has been going out of their way to avoid using the word “syncing” with regard to iCloud. That implies that files exist in one place and need to be moved. But … even that’s too technical for the story Apple is weaving. With iPad/iPhone and now OS X Lion, you don’t save documents anymore. They save automatically — but an easier way to think about it is that they just exist, as is, in realtime on all your devices…

Files are something Microsoft worries about. Files in the cloud are something Google and Amazon worry about. Apple’s iCloud is about opening an application and the thing you want to access being there.

Business Insider’s Pascal-Emmanuel Gobry in For Google, iCloud Is Annoying; For Microsoft, It’s A Humiliation

Here’s how Google and Apple’s vision of the cloud differ: for Google, the cloud means cloud + web; for Apple, cloud computing means cloud + software, with the internet stuff happening behind the scenes.

All of the cloud computing services Google offers to consumers, like email, word processing and spreadsheets, happen within the browser. To Google, the point of cloud computing is to replace desktop software with the web.

For Apple, cloud computing doesn’t replace software, it augments it. All of your email, data, songs and stuff is automagically synced to the cloud so that you don’t have to do backups and you can access it anywhere. To Apple, the point of cloud computing is to make the software better.

That also happens to be what Microsoft has been saying (but not really doing) about cloud computing forever…

This is an alternative vision to Google’s and also a powerful one, as Apple has shown. You can create an environment that’s “the best of both worlds”: the richness and user friendliness of desktop software, and the advantages of cloud computing (autosave, syncing, no backups, access anywhere)…

For Google, iCloud is an annoyance, because it makes iOS even more appealing to consumers vis-à-vis Android.

For Microsoft, iCloud is a humiliation.

Asymco’s Horace Dediu in The Five Year Plan:

These data centers essentially act as a protective moat around the [high-margin] iPhone business. So instead of having to fight on lower price points, they say we’re going to enhance the experience with our cloud strategy and allow users to have an integrated, smooth and pleasant experience — which is what Apple is known for — without having to reduce prices… Google may have the components necessary to deliver similar experiences, but it’s not going to be an integrated whole as Apple offers. So again, Apple is ahead by maybe 2 – 3 years.