Well, I returned two TC-P42S1's because I couldn't tolerate the buzz. Then I went with the TC-P42G15 and the buzz is still there, only it seems to be less noticeable (and the picture and features are more attractive than the S1). I've also heard of people mentioning the buzz with the V10, so I can only assume they all do it. Some people may be more sensitive to high frequencies, and it may depend on location.
I got to thinking, when I set up the G1 in the living room I didn't notice the buzz unless I went around back of the set. When I put it in my bedroom, there it was again from a viewing distance of 14 feet.
I have it in a quiet room, in a corner, about a foot away from two walls. I stood in front of the TV paused on a bright screen to hear the buzzing. I then held a blanket behind the TV, and, even at that close distance, I could barely hear it.
So apparently if you can hear it at a substantial distance, it's all about reflection from the wall. Right now I have a blanket on the wall and the buzz is no longer an issue. I plan on getting high-frequency acoustic foam to hang where the blanket is for aesthetics.
This worked for me and I'm finally satisfied. As long as the sound isn't reflecting off the wall, it stays behind the set.