While using the iBook G4 for all things the MacBook Pro sits there, downloading stuff and doing other things that don’t need my attention. Annoying: that whinning noise. Disabling the 2nd CPU with ‘chud’ helps, but when the thing goes to sleep it does forget it. Another observation is that when the screen goes dark the noise goes away as well. Try setting the brightness to low and it stops.
As an extension to the ‘old people can’t hear high frequencies meme’ I think that the MacBook Pro does have this annoyance since Jobs simply can not hear it. His ears are not as sharp as his mind people say. That’s why the iPod is so loud, and that’s why is claiming that he replaced his fancy rich-man-stereo set with that thing called ‘HiFi’.