some points I which may provide some synthesis for agonisers I hope:
Re "systems built around dual-core Intel CPUs remain a little more energy-efficient"
The vast majority of desktop mobo customers opt for graphics integrated with the mobo (igp). Do not quote me but I am pretty sure it is above 80% of desktop mobo sales.
AMD/ATI are clear leaders with their 55nm (soon to be 40nm I am guessing) chipsets on the 780g and 790gx. Intel igp is pathetic. Nvidea igp chipsets for Intel CPUs are a bit better and has a slight advantage in audio for the purists, but power consumption sucks since they cant match AMD chipsets' 55nm technology for starters.
Personally, I also feel more comfortable buying such a "platform" from one company than risking two companies (who are at each others throats), playing "the blame game" to avoid responsibility for my potential problem.
In this review, power consumption was equitably tested at the wall, but it should be stressed that AMD has for years used the clearly superior strategy of placing the memory controller inside the cpu to acheive much better memory bandwidth compared to (until the i7 (definitely not budget category)) intels limited FSB system. The memory controller draws significant power and generates heat of course. This allows intel to publish misleading cpu power/clock numbers, because they transfer this load/heat to the mobo chipset.
For those who doubt AMDs future viability, it seems to me that the Athlon is not only very economical, it is cheap to manufacture (unlike phenom x2 and x3). It could be very profitable for AMD.
see also - budget gaming system - ~"for the price of an equivalent Intel CPU alone, an AMD CPU and mobo can be had"
Historically, you have a far better chance of upgrading your CPU without having to replace your motherboard with AMD than with Intel. Many power users use "budget" components, they just upgrade more frequently.