Finally, and this is a big one, CSS Page Grids drastically simplifies the task of CSS page layout by offering a set of seven reusable, stretchy, two-column page layout templates with headers and footers. Each column can be further divided into vertically stacked sets of sub-columns using
<div>s with a set of predefined grid classes for various percentage widths.
Although Yahoo! does not provide any, it would be very practical to produce pluggable style sheets to apply visual formatting to the page layouts produced using CSS Page Grids. If this layout technique gains traction, I would expect a site skinning community (if not a commercial market) to spring up around such styles. This approach to laying out pages is also readily toolable, and supporting them is the next logical step for WYSIWYG design tools like Dreamweaver.
The update to the Yahoo! Design Pattern Library has vastly expanded it, roughly doubling the number of design patterns it contains. Most of the new patterns are grouped under Invitations (ways of signalling the presence of an interactive feature) and Transitions (ways of signalling a change in the application state).
Community initiatives like WebPatterns are moving at a glacial pace to ensure that everyone gets their say in defining the language of web design. Meanwhile, Yahoo! has thrown caution to the wind with the Yahoo! Design Pattern Library, and looks set to define the de facto standard in Web patterns before WebPatterns and its ilk even get off the ground.