To those less informed on the whole situation: The simple fact is that Flash isn't going anywhere for a long time, but at the same time, implementation of HTML 5's features is quickly going to become far more pervasive (we're already starting to see this). You, of course, have people from both extremes arguing both sides ("Flash is dead!"; "HTML5 will never get anywhere!"), but if you're really listening to just these opinions, you're only going to get a very polarized view of the situation.
Sit down, read the HTML 5 specs, keep up with the latest HTML 5, Flash, and major browser updates, and you'll get a better picture of the situation. Listening to people like this Radley Marx really does not give you an informed or balanced view of the whole situation.