I don't hear any "whine" at all, though I can hear a high-frequency hiss on songs I normally don't. I can't hear it with the iPod headphones, but it becomes really apparent with my Sony inner earbuds.
The iPod phones just have a really, really weak top-end and Apple may have brought that up through the hardware to compensate.
I'd hate to have to go in to many of my 1500 songs and reduce the high end in the iTunes EQ.
There is a whine from the drive itself, though you can't possibly be hearing that with your headphones on and music playing...
Anyway, back to the topic of firmware, did you know you can change the pictures? I'm working on changing the logos in the about box, as well as the text, and I'll post pictures some day. For more info, check out <a href="http://www.ipodhacks.com