Well , we have vastly increasing screen resolutions as demonstrated by the new iPad not to mention easy zooming etc.

I'm not necessarily suggesting that you entire program will be converted to a diagram overnight but it might be an interesting way to declare general structure.

I've designed algorithms via OmniGraffle similar to this, though had to manually write the code later. It's an interesting way to do things, and it does seem to make designing complex things easier.

Yet almost every software project I've been to has started with boxes and arrows on a whiteboard. What if these boxes and arrows would be the executable application? And what if you could go to a running application, see how it is connected, and how data flows between components?