Well, let me say up front that I am bitter about my macbook and you should judge my comments accordingly. But you should also know that I am bitter because of the problems its had; I bought it with great joy and high hopes.
I know people are going to say that many macbook owners are happy and only the people with problems post. However, I can only speak to my experiences, and none of the problems my MB is having is unique to me. Also, regarding the whine in particular, it is my belief that it's on every single macbook, as I've never heard one without it. I'd bet 2 to 1 that people who say they don't have it just can't hear it either because it's too high pitched, or because they use bluetooth accessories, or because they don't use it in a quiet place.
My macbook had the discoloration issue, which apple, to its credit, fixed promptly. However, it also has a loudish whine, a moo, and it randomly shuts down sometimes (bad logic board). On a 2 month old machine, this is totally unacceptable.
Many things about my macbook are wonderful - the screen, the keyboard, the speed, the appearance, the isight and front row, etc. But in my 10+ years of owning macs, this is by far the most problematic one. I absolutely would not recommend a macbook to anyone until apple gets its quality control back on track.