While presenting an interesting thesis, the book missed many opportunities at greatness. Why? The genome analogy was almost completely squandered, probably because genes represent traits and not capabilities, as the authors suggest. (Perhaps the authors could compare 'centers of excellence' to organs, with genes being the traits those organs exhibit which separate world class organizations from also-rans.) But I didn't write the book, so, ok, the authors get the benefit of the doubt.
However, the notion that a company that exhibits a world-class capability should soul-search to figure out "what business they're really in" is overly simplistic. The business world is littered with companies that forgot what business they were in, and have since succumbed to their more focused competitors. It is the alignment of culture, strategy and workflow that characterizes great companies, not fitting square pegs into round holes by making wholesale strategic shifts because "we happen to be great at shipping or inventory management or product design." It is these areas of excellence that make otherwise mediocre companies stand out against their competition; packaging and selling such dominating capabilities could prove lethal. How? The notion of packaging a core capability misses an important counterpoint to the enthusiastic promise of the subtitle: Unlocking the value of your business, to be sure, might allow unwanted trespassers.
This book provides much in the way of theory and the ideas presented are valid absent any specific market context. Applying these ideas in the real world, however, is risky, expensive and challenges the notion of cyclicality - that a business varies between reliance on partners (outsourcing) and doing it all in-house because markets demand it or competitive threats command it. Once that dominating capability that you have so carefully packaged and marketed is matched by a competitor, you're back to square one, having forgotten your original business base and left to rethink exactly what business you're in. Again. Sticking to what you're good at is no doubt good advice; sticking to what you're passionate about is better advice.