HTML 5 offer a rich features, such as video and audio playing capabilities, without using third party plug-ins. Beside that, HTML 5 also offer form validation capabilities. Check out the usage example in this post. The only drawbacks of HTML 5 right now is the support only provided by latest browsers. Hopefully the majority of internet users have switch or upgrade their browser to version that support HTML 5, so all of HTML 5 features can be used maximally.
