I took another quick look at the F8000 tonight in Best Buy, hoping they moved it to a better location than near the ceiling (they didn't). There is now no question in my mind that the set still suffers from some form of CE-Dimming or auto-dimming, because it was plainly visible multiple times during the few minutes I looked. As I mentioned before, the set was of course on demo mode, so the tv-generated sales-pitch menus were popping up all over the edges of the screen, whenever the Best Buy feed would fade to black between clips, those tv-generated menus would dim to a fraction of their regular brightness, and pop back to full brightness as soon as a new clip faded in. This is classic CE-Dimming behavior. The white text, the grey backgrounds of menus, they all dimmed instantly upon a black screen. My girlfriend saw it as well. I don't see how anybody could not see just by walking into any Best Buy and watching the screen for 5 minutes. Just pay attention to what happens to the edge menus that pop in and out in demo mode.
This makes me very nervous. What happened to that new technology that promises keeping the screen deep black without affecting bright areas of the screen? I call shenanigans.