In the next version of OSX, Leopard 10.6 Apple will change the gamma from 1.8 to 2.2.

-"Default Gamma Changes

To better meet the needs of digital content producers and consumers, the default display gamma has been changed from 1.8 to 2.2 in Snow Leopard. Applications that override the deftault and assume a gamma 1.8 setting may have different onscreen and printed output than they did in previous releases of Mac OS X. Please report any visual differences that you encounte"

http://news.worldofapple.com/archives/2008/10/25/...