This looks a little overengineered to me. I'm always suspicious when I see a lot of 'envelope' code but no examples of code that actually does anything -- it reminds me of the guy who wrote a blog post about developing a sudoku solver with TDD who got to the point where had a few tests, but he never finished the app.

In this case we're seeing a few snippets of code, but no real sense of the structure of the app other than to see the particular way that 'main' gets called. In particular we get no information about how they've solved the difficult problems, such as how to organize complex asynchronous activities. (That's the scaling problem in Javascript, Flex, Silverlight, GWT, etc that used to keep me up at night)

I'm also a little disturbed that he wanted to write a DOM abstraction layer. Today there are many libraries such as dojo and jQuery that abstract away some of the worst problems with the DOM and with XHRs. Most of us could complain about the details of said libraries, but I'm very happy that other developers are doing the hard work to ensure browser compatibility, which is a real, not a hypothetical problem.