There are some new structure elements introduced in HTML5 which are useful to structure web page.

<Header>: Use to illustrate heading and subheading

<Footer>: Describe the Footer of a website

<Nov>: This element describes the navigation part of the website

<Article>: Define specific part of a website like testimonials, etc.…

<Section>: Use to define a group of articles on the website and also useful to define different sections of a single article.

<Aside>: Define a block of content which is not a main content but related to a main content

I am interested to see how the new markup will effect backwards compatibility and graceful degradation.