This is what people in the know call the next step in web evolution. What does this mean for us programmers? Well, it means a simplifying of server function. More accurately put: it means server portions of applications will need to specialize around the data they are concerned with. No more highly customized data for the UI. This is what is lending itself to DFD (Design First Development). While DFD is a logical future step, it may not be the best design tactic for enterprise applications. As Joseph Moore brings out, it doesnt work well for scale.
Still the UI is coming back into the limelight as the driving force behind applications. My latest project is moving forward because of a nifty JS/CSS/HTML only mockup. Because I started there, I know that I can simplify my server code. I don’t want to say that DFD is the way to go, but sometimes it does help to consider it.