[muglug]

As much as the idealist in me would love to disagree, this is the fundamental problem.

As stated elsewhere in this thread, agency clients are used to a diet of static Photoshop mockups, and I can't see that expectation changing anytime soon.

What might change are the tools - it's in designers' interests to save time, and tools that allow designers to create mockups for different screen sizes whilst still maintaining the flexibility of Photoshop are beginning to emerge. But it'll take a few years, at least, for those tools to reach maturity and enjoy widespread usage.