On my R61, I believe I remember hearing this, but I also remember where I found something that stopped it.
In the Power Manager (The Lenovo one), edit a power plan and disable the 'CPU Deeper Sleep'. See if this makes a difference.
My CPU is a T9300, so newer processors still have it. I'm sure it's actually the motherboard, not the processor. Probably the processor power regualator making sounds when the processor current draw changes rapidly.
i too have the problem of a whining c2d thinkpad.. hope this problem will be fixed the real way. no rmclock workaround and stuff, but i think this would involve changing all the whiny motherboards so i guess so it ain't happening
but i really hope you guys find a way to do it!
(btw. i hate it when people tell me how my pwd has to be like..
I've found that with other Core 2 laptops ive used enabling RMclock's HLT command when system is idle silences my systems. From the management tab check "Run HLT command when OS is idle". Reboot and the noise should be gone.