Gamasutra's Chris Remo has a nice interview up with Mirror's Edge producer Nick Cannon on the design ethos and process of putting together the game; a lot of the interview is taken up with design considerations and the nuts and bolts of how the game was built, but there's plenty of interesting chatter in throughout. On the issue of the codification of genres and a rigidity in design that seems to be passing, Cannon has this to say:
Try and — you can't always make something different just for the sake of it, but try and be creative, and do something unique. I think that's what gaming's all about; I think that's what we're here to do.
And I think at times it's great to mimic real life — there's no bigger fan of sports games than myself, and I want them to be real, clearly. I don't want them to play different; if I'm going to play football, I want to play football. I want to play it as it is, you know? It's great for me; I love that. But, in the other genres, I think in certain circumstances, there's a real gap to be unique, and be different, and be creative.
Worth a read through whether you're awaiting its release or not. I always find reading about the various design processes and considerations of different teams to be enlightening at the very least.