It really depends on the application. Remember, the client is always untrustworthy. You can trust them with their data, but nothing else. In three-legged cases, like an ad or some other third-party developed app hosted in your page, you can't even trust the client-side to have unlimited access to the client's data! Plus, there are remote script hacks that potentially will compromise the user's state or other information.
a catchy acronym for what all the cool kids are doing in the browser with Javascript
At Yahoo, we call it Progressive Layered Enhancement. Start with working markup and server-side logic, and then enhance it in layers to add functionality for the browsers that can handle it, so that it always works, even if a layer is missing or broken.
Having worked on a Microsoft stack in the past, I can say that it was nice to have a single language from end to end. It just really sucked that the language was VisualBasic. So, I get the excitement behind GWT and Pyjamas. Not that the author is wrong, I just think he doesn't really treat the material very well.
PLE! We have our catchy acronym :).
Good point about the security implications. That must be an integral part of any web application design methodology. For traditional kinds of desktop applications, that wasn't so much of a concern.
In my day job, we have a Java back end with a lot of user interaction implemented with Javascript in the browser. Data access server side stuff actually plays to a lot of Java's strengths, I think, and the more dynamic nature of Javascript is a good fit for DOM manipulation in the browser. I'm not sure I would want to pick one of them to run both places.
cool. very few people do! and don't forget rubyjs / rwt.
"Not that the author is wrong, I just think he doesn't really treat the material very well"
well, you can't have everything :)
REST may be the applicable acronym for the server side (or at least, one design for implementing what you describe). But I haven't heard any design patterns with a catchy acronym for what all the cool kids are doing in the browser with Javascript. Perhaps that's for the best. Often a catchy acronym is a sign that a technology will soon either stagnate or be considered passe.