My motivation for posting this was to share a neat idea for a product. If someone could get into this market, and fast, I'd bet they'd have a solid business.

Let me know when you launch—I'll be your first customer!

Have you checked out Dashcode that comes with Apple's SDK? It does some webkit-only hooks in the HTML/CSS/JS it generates, but as a real-life example of what you suggest it comes pretty close.