About so-called WebOS/Webtop apps, Nova says:

People don't want to manage all their information on the Web in the same interface they use to manage data and apps on their local PC. The Web is an entirely different medium than the desktop and it requires a new kind of interface. The desktop of the future - what some have called "the Webtop" - still has yet to be invented.

Right on.  The nature of data is different on the Web.  The file-folder paradigm just doesn't work anymore, especially when you don't own a lot of the data you're using (I would estimate the ratio of using to producing data is something like 20 to 1).  This is not the domain of files on a hard drive, it is the domain of globally-accessible information in the cloud.  The world is no longer flat, but the desktop, and the current crop of applications, are built for only two dimensions.

As we move into a world that is increasingly mobile, where users often work across several different devices in the course of their day, we need unified access to our applications and data. This requires that our applications and data do not reside on local devices anymore, but rather that they will live in the cloud and be accessible via Web services.

Yeah, I agree.  But it shouldn't stop with just the data... I want personal Web services in the cloud that can be reached at any time as well, that can manipulate my data.  Don't touch my data yourself, I'll handle it for you, thanks.  Problem is, it's the Wild West out there right now. While the standards are out there, developers don't see why they would benefit from using them yet.

Then he loses me a little bit:

If these trends continue, will the browser eventually swallow up or simply replace the desktop? Yes. In fact, it will probably happen very soon. There just isn't any reason to have a desktop outside the browser anymore. What we think of as "the desktop" is really just a perspective on our information and applications - it's really just another "page" or context in our digital lives.

Well, maybe.  However, there are still a FEW compelling use-cases for desktops versus the Web:

• Games
• Low-level hardware requests (for using new hardware)
• CPU-intensive applications (such as Photoshop and Premiere)

While I agree long-term (talking, 5 to 10 years out), I think browsers have a ways to go before these types of apps can run in browsers, and be stable.  Flash helps, but it's not there yet.  There are some things like thread handling and memory management that browsers still rely heavily on the OS for.  But yes, eventually I can't see why you wouldn't plug a browser OS CD into your bare-bones laptop and run everything you need from that.

The desktop of the future is going to be more concerned with helping users manage information overload - particularly the overload caused by change. In this respect, it is going to feel more like an RSS feed reader or a social news site than a directory. The focus will be on helping the user to manage and keep up with all the stuff flowing in and out of the their environment.

Nah, c'mon, this is a bit of a reach.  We did plenty of stuff on desktops before we were connected to the Net 24/7.  Not only that, but unless you're a reporter how would you get an ACTUAL WORK done if your OS was constantly pushing things in your face?

The Webtop is going to be more socially oriented than desktops of today -- it will have built-in messaging and social networking, as well as social-media sharing, collaborative filtering, discussions, and other community features.

Agreed, but this DOES require the death of social networks as we know them, because their features will just be foundational elements absorbed into the infrastructure needed for this "Webtop".

Our next-generation shared spaces will be nestable and linkable like folders, but they will be far more powerful and dynamic, and they will be accessible via HTTP and other APIs such as SPARQL enabling data to be moved in and out of them easily by other applications around the Web.

Interesting. I like the idea of spaces with only certain participants, but doesn't this require a much finer level of security granularity than any consumer is used to using?

One of the most important aspects of the coming desktop is that it's going to be smart. It's going to have to be. Users simply cannot handle the complexity of their information landscapes anymore - they need help.

Why does everyone keep SAYING this?  No, you don't need a pill to help you lose weight, you need to cut back on what you eat.  Simple.  Eliminate the noise, or find someone who will filter it for you.  Not like there's a lack of people doing that these days...

The Webtop is going to learn and help you to be more productive. As you use it, it's going to adjust to your interests, relationships, current activities, information and preferences. It will adaptively self-organize to help you focus your attention on what is most important to whatever context you are in.

I have yet to see this work well.  If the application moves something because it's trying to figure out where I would like it better, I inevitably get pissed off because it's not where it used to be and have to go hunt for it.

Your desktop will actually be a semantic knowledge base on the back-end. It will encode a rich semantic graph of your information, relationships, interests, behavior and preferences. You will be able to permit other applications to access part or all of your graph to datamine it and provide you with value-added views and even automated intelligent assistance.

Ah, now THAT's cool.  Give the man a cigar!  Why do I think Kingsley will have something to say about this :)

Information that is considered to be personal and private in Web site X should be recognized and treated as such by other applications and websites you choose to share that information with.

You're making this too complicated.  You just got done talking about storage in the cloud, why are you going back to the hard drive-based application model now?  I want MY data in MY storage.

The semantic web provides a good infrastructure for building and deploying a decentralized framework for policy and privacy integration, but it has yet to be developed, let alone adopted.

Developed, yes.  Adopted, no.

No discussion of the future of the desktop would be complete without delving into the topic of the WebOS.

Oh, no.

Many of the services that comprise an operating system are already available as Web services, but they are not yet integrated into a single cohesive WebOS. However it seems clear that the major players are aware of this opportunity and are positioning their services to capture it.

I think that fact pretty much guarantees the death of "WebOS" as a potential buzzword.  I'll just wait for Microsoft to come out with one and that term will die within two years.  Thankfully.

I like Nova's ideas... some of them are exactly what I've been saying for a long time.  However, he still has a little too much of the old Microsoft thinking that he needs to rid himself of.  Whatever this thing ends up being he's absolutely right that it won't look anything like a current operating system/desktop, but rooting those old constraints out of the design process takes a lot of mental work.

I'd like to add that I also really hate the word "Webtop" :)