Cadence and the Magic Number of 180

It seems that everyone has been told that the ideal cadence is 180 steps per minute. The great Jack Daniels himself has stated that a slow cadence is associated with overstriding and increased injury rates. For a long time, this has been undisputed. A cadence of 180 was king. However, lately this magic number seems to be something people are questioning. Is a cadence of 180 really ideal for every person at every pace?