In our environment, the idea that "If we have enough Tiger teams, we can design the whole thing for a year, then release some Word Docs and PPT and Excel spreadsheets with requirements and then we're done" still reigns supreme. We end up taking requests and turning them into hideous spreadsheets/tables and "traceability matrices" that are basically outdated as soon as the first line of code actually gets written.
So the idea of BDD-style "requirements" seems to make a whole lot more sense - if I can check my 'requirements' into CM right along with my code, perhaps I can convince all these working groups that we can start building on day 1 (or at least day 15).
I guess my question is, how often have you seen Cucumber make the leap from developers-write-it to its-used-in-planning-by-architects-and-program-managers? That's obviously part of the ideals of the project, but how often does it become reality?