That article made me try out Google calendar, but I am severely disappointed. It really is just a calendar - duh... I would have expected an Outlook replacement with task lists and stuff like that. The functionality seems to be the bare minimum. I haven't tried to share my calendar, though.
It was an okay write-up, if not overly obvious. I hope he realizes that Google isn't the only source for desktop alternatives, webapps or otherwise. I (along with approximately everyone here, so I'll spare them the effort of listing the obvious candidates) can list several popular ones off the top of my head that beat Google, in my opinion. And not all of them are YCombinator startups either. Hooray for diversity!
GMail -- they aren't the only email provider, but certainly a leader. You can't really go wrong with using it, unless you have major privacy concerns. But then, why are you using email to begin with?
Google Reader -- There used to be feeds.reddit.com, but now that I check it seems to have been taken down; what a shame. I thought it was a really good idea, though it had been freaking slow when I last used it. Using Firefox or Opera, there are already means to just integrate feed-reading into the browser. I find that this has suffices. It's no more or less centralized than opening a webpage to use a reader when you're already in your browser in the first place.
Google Calendar -- kiko.com seems to still up and running, though of course they ran into trouble at the hands of Google Calendar. Then there's http://www.30boxes.com among several others.
Google Talk -- meebo.com doesn't suffer from problems he mentioned with Google Talk, so it actually beats Google in my opinion. There are others, but they don't seem to be as good as meebo, in my opinion.
Google Docs & Spreadsheets -- this is a tougher one when looking for actual online solutions, I think, just because the current online suites aren't as full-featured as the desktop equivalents. http://en.wikipedia.org/wiki/List_of_office_suites#Online_office_suites seems to be a good place to start, though. Plus, I hear those zenter.com guys will be killing PowerPoint. ;) If, however, you're looking for interoperability then OpenOffice.org works wonders.
Google Page Creator -- not mentioned in the post, but weebly.com seems to excel in this field anyway, so they're (more than) worth a mention.
Really, I think a lesson to be learned is that just as there are different apps you could use on the desktop, there are a lot of webapps to choose from. I would think this would be particularly apparent as ubiquity in desktop applications seems to be flawed. If it weren't, people would be more inclined to use pre-bundled software on Windows instead of OpenOffice, AbiWord, The GIMP, Pidgin (still have to get used to that), Trillian, Firefox, Thunderbird, Opera, and so on. Moreover, if it weren't flawed then some webapps might not exist! That, and the thinking that somehow there has to be an ultimatum between desktop & online applications seems fundamentally silly. Not to say that what can be implemented in one can't be implemented in the other to some extent, but you don't need to have all of your applications be solely on one platform. Freedom of choice and all that fun stuff. Certainly the internet provides a platform that has several distinct advantages to the desktop, but that doesn't mean you absolutely must lock yourself into it; though, more likely than not, as webapps continue to become more advanced the preference shifts mostly towards them instead of the desktop.
In the meantime, he and I are stating what most people should already know. And if they don't, that's probably why he did this story (and why I'm commenting about it) in the first place. I didn't really mean for this to turn into a list, but proof by counterexample is a quick & easy method in this case.
Poignant Summary: webapps are immensely useful, and you don't need Google to prove it.
