Apple are supporting the open standard architecture "hypertransport" for their system interconnects. So far this is only on the G5s (PowerMac, iMac, xServe) but will probably be on the next generation of laptops as well.
See
http://www.hypertransport.org/ for more information.
As you can see, its more a question of Intel releasing Sonoma in response to AMD, Apple, Cisco, NVidia, Sun and Transmeta.