New Feature of HTML 5
- output element
- Custom attributes
- header element
- section element
- article element
- footer element
- mark element
- Supported attributes detection (JavaScript feature).
- Regular expression and required attribute for input element.
- audio element
- video element
- autofocus attribute
- hgroup element
- Local Storage support for HTML 5 (not a feature of HTML 5).
- placeholder element for input.
- Input types extended to email, date time.
- contenteditable attribute which takes the advantage of local storage.
- No need to mention the type attributes for script and link element.
- small element
- figure and figcaption element.
- Simple DOCTYPE element.
You can learn more about HTML 5 here