As you certainly know, ActionScript 3.0 is based on ECMAScript language. The new edition of ECMAScript is in preparation (ECMA-262 Edition 4) and will most certainly shape the future of ActionScript 4.0.
Colin Moock is going to do a lecture at FITC about these changes. You can access his lectures notes ‘What’s new in ECMAScript 4.0?‘ or access to the ECMAScript documentation page to have more information on it. It’s also a unique way to get the preview of ActionScript future 🙂