If you haven't seen them yet, Apple has officially released the Universal Binary Programming Guidelines. There are some interesting tidbits in here. Most striking, perhaps, is that there's no mention of programming for 64-bit intel chips; the usage IA-32 is applied universally. We're still early in the process, though, and if the Intel chips really are going to hit the consumer products first, there's plenty of time for 64-bit integration. More interesting to me is that the x86 transition will seemingly be a shift away from an open source base. The core OS itself will seemingly continute to be Darwin, but the machines will apparently go back to booting a proprietary BIOS:
Macintosh computers using Intel microprocessors do not use Open Firmware. Although many parts of the IO registry are present and work as expected, information that is provided by Open Firmware on a macintosh using a PowerPC microprocessor (such as a complete device tree) is not available in the IO registry on a Macintosh using an Intel microprocessor. You can obtain some of the information from IODeviceTree by using the
No word on what the BIOS will be, but I think we can expect one of the standard PC options.