I saw this previewed at the CSUN assistive technology conference and thought it was pretty interesting. Instead of replacing the whole window with a text-scraped alternative, Google uses a sidebar that can be resized, and which sits alongside the main window. For some people, that will be a downside compared to the reader views offered by other browsers.
But the upside is that it offers more text/formatting customization options that other browsers. It's great that there's innovation coming to this sector.