Serge Cashman , May 29, 2006; 11:42 p.m.
Here's an interesting thread on the subject I stumbled upon on Colorvision's board: http://groups.yahoo.com/group/colorvision_group/message/981
Personally I think current Macs are all natively close to 2.2 just like PCs. And for that reason they are set to 2.2. The origin of the 1.8 gamma notion is unclear, according to one of the Colorvision's managers. DryCreek claims it's because old monochromatic macs were natively close to it...
I don't know anything about printer gammas though, so you may have a point there.