This is a lengthy story of the dev. history, a bit too starry-eyed, People-magazine-style for me: Photoshop News » The Shadowland/Lightroom Development Story. Pretty much my take on this whole thing is "Don't try this at home," and better yet, "If we try this at the office, can't we all do better?" Is it that hard to innovate, incubate, and manage the release of a new product?
Maybe one of the lessons here is "Make sure you've got a good UI designer on staff during the whole process." But I'm definitely biased on that reading.