The most important new feature is intelligent collapsing columns. i.e. If you don't publish any modules in the right column then the column disappears and the central content column expands to fill the space. This gives complete flexibility with your layout allowing you to have any combination of 1, 2 or 3 columns and also to vary the number of columns published throughout your site.
We have also cleaned up the CSS and included a couple of minor design improvements.
