I'm just starting to read my first books on game programming. Most of them introduce us talking about the huge jump from 16 bit to 32 bit. I would like to know if coding for 64 bit is or will be different from coding for 32 bit. Also, will it mean that i would have to learn windows programming all over again once, say, longhorn is out? Will directx and opengl programming change also? Sorry for not being technically accurate, but i jut have a basic notion on how bits affect programming. Thx for the help!

The jump from 32 to 64 is much smaller then from 16 to 32 (from the programming point of view). 32 bits is already large enough for almost everything. The APIs used for 64 bit operating systems (windows on amd 64 or IA64, linux, etc.) are basicly the same as the 32 bit version. The only thing to look out for is that the size of a pointer is no longer the same as the size of an integer.

And you will never have to learn programming all over again, programming will always be programming. And no matter what changes, your knowledge will still apply and the underlying ideas will still be the same.