We’ve got a tip off from a community member Nicolas Toussaint who has picked up a story from Tonymacx86.
‘According to netkas, Apple has dropped 32-bit kernel support altogether in Mountain Lion. Also, the article says most native kexts have switched to 64-bit only.
What will this mean for users? No more arch=i386 flag to boot 32-bit kernel mode, and lots of older machines will not be able to run the OS. Solutions are currently in the works- but right now users with incompatible machines will have to test with the Mountain Lion DP1 kernel.
Source: http://netkas.org/?p=1067
It seems Apple will be forcing everyone down the 64 bit route. Discuss