Last year, Google spent most of its I/O conference keynote talking about hardware: Android, Glass, and tablets. This year, someone seems to have reminded Google that they're a web company, since most of the new announcements were all running in a browser, and in many cases (like the photo editing and WebGL maps) pushing the envelope for what's possible. As much as I like Android, I'm really happy to see the web getting some love.
There's been a drumbeat for several years now, particularly as smartphones got more powerful, to move away from web apps, and Google's focus on Android lent credence to that perspective. A conventional wisdom has emerged: web apps were a misstep, but we're past that now, and it'll be all native from this point out. I can't disagree with that more, and Google's clearly staking its claim as well.
The reason the web wins (such that anything will) is not, ultimately, because of its elegance or its purity (it's not big on either) but because of its ubiquity. The browser is the worst cross-platform API except for all the other ones, and (more importantly) it offers persistence. I can turn on any computer with an Internet connection and have near-instant access to files and applications without installing anything or worrying about compatibility. Every computer is my computer on the web.
For context, there was a time in my high school years when Java was on fire. As a cross-platform language with a network-savvy runtime, it was going to revive thin clients: I remember talking to people about the idea that I could log into any computer and load my desktop (with all my software) over the Internet connection. There wouldn't be any point to having your own dedicated hardware in a world like that, because you'd just grab whatever was handy and use it as a host. It was going to be like living in a William Gibson novel.
I don't believe that native programs will ever entirely go away. But I do think we see web applications spreading their tentacles over time, because if something is possible in the browser--if it's a decent user experience, plus it has the web's advantages of instant, no-install launch and sharing across devices--there's not much point in keeping it native. It's better to have your e-mail on any device. It's better for me to do presentations from a browser, instead of carrying a Powerpoint file around. It's better to keep my RSS reader in the cloud, instead of tying its state to individual machines. As browsers improve, this will be true of more and more applications, just as it was true of the Java applets that web technology replaced.
Google and I disagree with where those applications should be hosted, of course. Google thinks they should run it (which for many people is perfectly okay), and I want to run them myself. But that's a difference of degree, not principle. We both think the basic foundation--an open, hackable, portable web--is an important priority.
I like to look at it in terms of "design fiction"--the dramatic endpoint that proponents of each approach are aiming to achieve. With native apps, devices themselves are valuable, because native code is heavy: it takes time to install, it stores data locally, and it's probably locked to a given OS or architecture. Web apps don't give us the same immediate power, but their ultimate goal is a world where your local hardware doesn't matter--walk up to any web-capable surface, and your applications are there. Software in the web-centric viewpoint follows you, not your stuff. There are lots of reasons why I'm bullish on the web, but that particular vision is, for me, the most compelling one.