Well, yes. But as FF+Chrome+Safari have more than a third of the marketshare, you can start writing parts of a website that work better with HTML5. For example,

Well, yes. But as FF+Chrome+Safari have more than a third of the marketshare, you can start writing parts of a website that work better with HTML5. For example, an application that uses the application cache to be usable offline, and tell IE users they could have an offline experience by changing browser. This means that everything still works, but people with HTML5 browsers will have a better experience.