Correct me if I'm wrong, but aren't you just talking about client-side rendering à la Dust.js? Send raw JSON objects to the browser alongside instructions on how to render them?
LinkedIn uses it to render half serverside half clientside.
No. You still have a Javascript and HTML/DOM engine in the browser. I'm suggesting the browser could be a kind of runtime environment a la JVM, not a combination of a compiler/interpreter and a platform.
So, basically applets / flash?
Close, but not entirely. Those still have some kind of library or runtime you have to be aware of, and require you to use a specific language. This is more like Parrot or the JVM, but designed with a browser in mind instead of an OS.