"The scripting layer is supposed to be swappable (that was the design of the DOM)."

That's a really good point to make. Not many people understand that javascript isn't necessarily related to DOM, it's only used to manage and manipulate DOM. The same thing could even be said of HTML - that HTML isn't necessarily related to DOM in the strictest sense. HTML is used to markup content, and provide content with meaning. It doesn't *have* to be rendered into a DOM context. All of this illustrates that HTML and JavaScript are not necessarily related to DOM, and that they're not necessary to create or manipulate a DOM structure. You could use an XML language and any other scripting language to dynamically access the DOM as opposed to HTML and JS. However, HTML seems like it will be the only markup language suitable for the web for ages to come whereas javascript is extremely dispensable.

Not many people realize this. I didn't realize this was what you were trying to get at with your quote at first, but now I realize it's very well put.