This is not a practical solution for the majority of web projects.

I don't know about majorities, but I do know about applications. bOP doesn't preclude using another templating mechanism. One solution we have used is to let the graphics folks generate their pages however they like. Once they get a design they like, we have them tag programmatically controlled elements, such as, "Login" or "Logout" or nav bars. We also have relied on style sheets to control thematic elements within the app.

I think it is important to address the issue of what controls the application. Most templating languages ignore this. Starting with the UI from a design perspective is fine. That's how we start most projects, and we build dummy models that load fake data. This allows us to prototype the workflow easily, and then we can fill in the business logic without changing the UI. BUT, what we don't do is let the UI guide the control flow. Our applications are task-centric, not page-centric (like JSP and many other toolkits). The advantage is that we can share business and presentation logic in interesting ways. You see an example of this in the petshop.bivio.biz where we reuse the logic for creating/editing accounts.

BTW, visit www.paintedsnapshot.com for an example of a graphics rich site that uses bOP. The artist and programmer were one in the same. The application was developed in a couple of weeks.