In regards to 4x4, what I don't a lot of people in general (not you specifically) don't appreciate is the additional costs associated with that approach. 4x4 is a easy route for AMD since it doesn't cost them anything, they just continue to sell their current processors, just twice as many, which is a good thing. However, how are motherboard makers going to take it? You look at an enthousiast board and those are already very crowded. It's going to be an interesting design challenge to put a 2nd socket and more memory slots onto a standard ATX board. The movement now is also toward smaller boards and smaller computers which doesn't help matters. The production cuts for such a board will also be very high due to the extra traces and probably the necessity to add extra layers for stability.
A lot of people point to 4x4 as a way for people to just buy the board and 1 processor now and add another later. The thing is that AMD seems to indicate 4x4 is only for the FX series, while people generally point to the ability to put a 35W X2 3800+ in it. Even if AMD opens the platform up it's unclear whether 512kB cache processors like the X2 3800+ will work. I've heard reports, which I don't know if true or not, that the 512kB models not only have their cache size reduced to save transistors, but also only have 1HT link. This means they can't operate in a 4x4 setup. Only the 1MB models retain 3 HT links like the Opterons. This would of course mean low cost, low power 35W X2 3800+ 4x4 setups aren't likely.
I'd be curious to see how much extra capacity AMD has to supply a 4x4 setup. They are already selling processors as fast as they can make them, and now they plan to be selling two of them at once. Having a single high-performing processor is much more worthwhile in terms of power, yields, and cost than selling 2 processors.