Well, at least kill the need for Flash on the iPhone? Daring Fireball says a simple "yes" to Yahoo! Tech's question.
The idea is that a standards based technology, open and broadly used, could make redundant proprietary and sometimes bloated and buggy plugins like Adobe Flash, Microsoft Silverlight, and Sun JavaFX.
Apple's Safari, including Mobile Safari on the iPhone, and Mozilla Firefox are already supporting HTML5 features. Microsoft's Internet Explorer -- so far -- isn't.