G. Michael Maddock and Raphael Louis Vitón have a thought-provoking new blog post at Businessweek.com featuring the top 10 reasons why new product launches fail. It's definitely worth reading.
My personal favorite on their list is what they call the "lemming effect" - i.e. companies decide to imitate their competitors' new products, rather than trying to truly deliver a distinctive product to the market. Me-too strategies are everywhere in the business world. Companies seem to so easily forget that enduring competitive advantage comes from distinctiveness, not imitation.