Meyer talks about the next web from a front-end engineering perspective. He explains how JavaScript will help build the next web on top of the web that aleady exists today.
The Next Web

For example, YouTube shows the movies in Flash but Flash movies are completely inaccessible to keyboard users. We are paralyzed so we need to bring back control to the user by adding keyword accessible controls to Flash movies:

Interesting example of how Javascript&CSS makes Flash video much more usable for people that can’t use a mouse, independent of Adobe. @kruithoph

In the visual realm ever since CSS has been created there has been a lot of talk about fonts. Scalable Inman Flash Replacement (sIFR) uses JavaScript to solve the font issues on the web:

sIFR is meant to replace short passages of plain browser text with text rendered in your typeface of choice, regardless of whether or not your users have that font installed on their systems. It accomplishes this by using a combination of javascript, CSS, and Flash.

Typeface.js does the same thing but without the flash and Cufon is a follow up project for customized fonts.

The JavaScript engine increased in speed due to massive changes. A huge amount of effort was put in the upgrade of JavaScript performance:

Modern Javascript engines, an order of scale faster than before, are not only interesting, but critical and potentially revolutionary @kruithoph

Eric Meyer announces the death of plugins as JavaScript will rule the world.

The Next Web