I tend to agree with the multitasking arguments here - run a game, virus app or other "normal" windows scenario together and see how the system goes, or for that matter, encode a dozen wmv files simultaneously. Encoding and copying video files to your psp or video ipod is a pain enough, but if you can do 8 of those in the same time it would take you to do one... now there I could see the potential in multi-core power.
Disappointment is an understatement. Intel simply had an unoriginal but interesting idea and went down the wrong road with it. Considering the emergence of enthusiast UATX and 10-slot designs, Intel should have used it's R&D to instead work on a CHIPSET - something that would allow enthusiasts/gamers to use just a single quad-core CPU, overclock the heck out of it, and combine quad-channel DDR3 memory and an ATI/nVidia capable quad-GPU 64-lane PCI express graphics solution within the Ultra-ATX form factor. Future-proof, if you know what I mean.
We all know the direction enthusiast/gamers are going, give us the hardware we need, and you will eventually get software that takes advantage of it.