If Im not mistaken, this is an intel problem. I dont know about the aluminum macbook but my friend bought a dell with the same 2.4 processor as the aluminum's and it does have that annoying noise. My black macbook does have it as well but is not as noticeable. For those of you that dont know what we are talking about, when the processor is IDLE put your ear close to the Q W letters in the keyboard. If your computer has it, then you'll hear a static kind of noise. Is not that loud and is only audible in a quiet room with your ear very close to the machine.
tubbymac, I know what you are talking about. I can hear the noise clearly but my brother, who is on his 30's cannot hear anything and he says is just me being paranoic.