OK... made a few calls at work.
The main reason for the Apple move didn't have anything to do with game consoles, it was about mobile chips. Basically, IBM can't make them for ****. Their lowest power offering was 45 watts and their 90nm process was not working to reduce that. Intel is offering a 22 watt laptop chip.
Also, the 64bit thing is false. Apple is going to work with the chips that are soon to be released by Intel. You could not design a whole new processor, tape it out, manufacture it, certify it and then release it in less than one year. 2 would be a stretch.