I found this graph explaining HTML 5 features via @obxdesignworks. Succinctly describes the major features enabled by HTML 5 that you need to be aware of: Canvas and video elements, offline storage and geolocation. The graph below shows a snapshot of current support and intent to support in web browsers. Shows that IE is well behind the field in terms of readiness as we speak, but IE 9 intends to support.

http://media.focus.com/images/uploaded/fyi/wtf-html5-infographic/HTML5__.jpg