Since OS is the main theme, I would like to ask if someone have information about how Microsoft is going to design their win64 API? What will actually be the changes between win32 programming and win64?, and what are the plans for FreeBSD,Linux about 64 bit processing ?

There are already linux ports to various 64bit architectures, including Alpha, Intel, and comming soon AMD.

http://www.linuxia64.org/
http://www.x86-64.org/
http://www.alphalinux.org/
http://www.kernel.org/