Hey, don't worry!
If you get a 430-series replacement you'll get an X1/Edge-type Chiclet keyboard!
With no option to replace it with a standard keyboard (as of yet or maybe ever)!
Isn't advancement great?
The problem is definitely connected to power management. Turning it off in the BIOS will get rid of the noise but on the T410s that's fatal to battery life.
There are two programs you can use to somewhat mask the sound. The first one is ThrottleStop
(download link is at the end of the first post, grab the latest version which should be 4.10).
One interesting tidbit that I found was that Lenovo has locked a certain area of the power management settings in this program. So we can't actually lock the CPU to only go to a certain C-state (i.e. to stop it from jumping back and forth millions of times a second which has been reported by some users to fix the whine). I don't know if we can get a BIOS mod that changes that unfortunate situation; there may be a site that does that work.
You might also try changing the "PowerSaver C0%" field- adjust the number to something like, I don't know... 80, then press OK and turn the program off and on again. That may lower the sensitivity on the switch that brings the CPU down to a lower power state; it might reduce the volume of the whine.
By the way- any Intel book you get can suffer from this. I believe it started with either the Core 2 or even the Pentium M- but I can't remember.
It's a problem you expect from 500-dollar Acer machines, not 1200-dollar ones, at any rate.
The 420-series doesn't do it as badly but the whine is still there on battery power (lower power gives more whine because of an inadequate capacitor).