A recent example of your second point is with Twitter lists, all Twitter clients became instantly obsolete, and the clients for the iPhone moreso since they wou

A recent example of your second point is with Twitter lists, all Twitter clients became instantly obsolete, and the clients for the iPhone moreso since they wouldn't be able to push an update for 2-3 weeks, as a developer I would find that extremely dissatisfying since I wouldn't be able to give my customers the best possible service.