It looks like the problem lies in the conflict between the Am3 CPU's and the Am3+ Boards.
I feel you have probably hit the nail on the head with this Night Gyr. I believe the new 9 series boards and newer 8 series boards with the AM3+ Socket, have been designed primarily with a view to the new AMD Fusion FX AM3+ CPU's and not for the existing AM3 processors. Backwards compatibility is always going to present some issues and I wonder how people would feel if these boards were only designed for AM3+ Processors with no backwards compatibility, in the same way that Intel releases their new CPU designs.
I feel the real test for these motherboards will only come when the new CPU's are available and that it is only then, that we will see their true strengths and weaknesses. I am not dismissing the current issues or ignoring them but I am a realist and it is obvious to me that, changing the socket design and the power design is not a task undertaken lightly and it is bound to have an impact on the existing technology. The Vdrop issue is more noticeable on the current 6 core CPU's than on those with four or less cores and the reason for this must be in the basic design of these processors. If you lock off two of the cores in these processors then the Vdrop is not so dramatic.
At present, as individuals, we do not know any firm details of the new AM3+ processors or their full specifications. The motherboard manufacturers must have more details and AMD would have supplied them with technical guidelines as to how the motherboards are to work. I would assume, that is the reason for the current problems and it is not down to bad design or faulty components.