First out is text-stroke, a new (and non-standard, so not for real-world use) CSS property that can be used to control the fill and stroke colours as well as the stroke width of text. A description and a couple of examples are available in Introducing Text-Stroke.
Take a walk through the woods and learn about all things HTML5. Starting with the JS APIS (selector API, storage, appcache, web workers, web sockets, notifications, drag and drop, and geolocation).
Then delve into the new HTML semantic tags, link relations, micro data, ARIA, forms, audio and video, Canvas, and WebGL.
Finally, the holy trinity finishes with CSS and selectors, fonts, text, columns, stroking, opacity, HSL, rounded corners, gradients, shadows, backgrounds, transitions, transforms, and animations.