The first article examines HTML5 features and their respective security implications. The article introduce you to the world of changes and the uncertain future that it holds as 0days are bound to come up as new cool features emerge.
In the second article Ivan explains the new security features of HTML5 and some of the newly created vulnerabilities. He concludes by stating that HTML5 is a living standard changing over time but can be patched up while new security holes can emerge in the blink of an eye.