You can easily make some blocks to use full-screen width with in the Site Editor. This page demonstrates this feature.
Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat. Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit. Duis autem vel eum iriure dolor in hendrerit.