Brian Marick blogs about Rick Mugridge's DoFixture for FIT and says:

I strongly prefer Fit tests to be business-facing, written in the language of the business instead of the language of the implementation.

I agree. Automated acceptance tests should test the business functionality without any regard to implementation details. In fact, I've been thinking about yet-another-test-framework for enabling this kind of automated, business-language oriented acceptance testing (too bad there already is a Sourceforge project named "bloat"...). It won't have true technical advantage but I do think it might fit some situations quite well -- including mine, depending on whether we could get the customer participate in authoring the tests (which we haven't, yet).

I've already done some fundamental plumbing but there's a lot of stuff that I haven't done or haven't even thought about yet. I'll try to squeeze in more work to put together something usable within the coming months. Feel free to remind me every now and then...