I don't think there has been nearly as much change as Rebecca suspects. It sounds like her skills have improved significantly, and that she's projecting this onto developers at large, but I doubt there has been much of a change in general.
For example, while XMLHttpRequest was introduced in 1999 (IE 5), it took years to gain traction (XHR support was added to Opera with version 8 in 2005), and incidentally, JavaScript frameworks (Prototype 2005, jQuery 2006) and distributed version control (Mercurial, Git 2005) entered the spotlight at the same time.
While serious JS-based applications were definitely around before the advent of Web 2.0 (you can go a long way with hidden iframes, long polling, chunked transfer, forms, 204 status code), these were the exception, front-end work was mostly about layout and code-reuse virtually nonexistent.
I do think the profession of "front-end development" has grown up a whole lot in the last couple of years. There have been front-end pros since long before I was even in the business, but I think the profession as a whole is being taken more seriously, and a set of baseline expectations for people in the profession is solidifying.
Then I agree with you, web publishing did not change that much, 3 years ago it was a bunch of js plugins together + nice html templates and well, it is still that currently. And I know loads of front-end that only know basic js with a svn client and get by.
Then you got js web apps. There you got a world of difference. It is limitless and evolving like crazy