PhilipWadler's Law of Language Design:
In any language design, the total time spent discussing a feature in this list is proportional to two raised to the power of its position.
-- http://www.informatik.uni-kiel.de/~mh/curry/listarchive/0017.html
This is largely a special case of the BikeShed phenomenon: Wadler himself makes the comparison at http://wadler.blogspot.com/2006/01/bikeshed-coloring.html
See also: BikeShed