At The Northern Union we believe in Products not Projects. Software is never totally "Done" just like a lawn is never totally "Mown" - there is always more, maybe not now but in the future.
A project is a fixed scope, known constraint and requirements piece of work. Packaged software implementations, desktop upgrades and telecoms changes are examples of good candidates for control via project management techniques. Software on the other hand is not.
Software in the Internet age is a constant rolling programme of incremental changes, where the priorities for the next developments shift over time as appreciation of user needs and market understanding also increases over time. Therefore an approach that manages development from the point of view of a product in the hands of users rather than a project to be controlled and blame assigned is more naturally aligned with the work itself.
Some things never change though. Great communication to and from all stakeholders is always critical and the lack thereof a cause of friction and waste.