Elliotte Rusty Harold has written an excellent article on HTML 5:
Eight years is a long time to wait for new features, especially in the fast-moving world of the Web. HTML 5 restores some of the excitement of the early days when Netscape, Microsoft, and others were introducing new elements every other week. At the same time, it takes a much more careful approach to defining these elements so that everyone can use them interoperably. The future looks bright.