For some reason this scenario reminds me of the way audiophiles greeted both DVD-A or SACD; they stayed away in great numbers, and opted for the CD instead. SACD and DVD-A introduced lots of new *features* that audiophiles didn't need, like copy protection, multi-channel sound etc., and featured them on a line of fairly weak, but expensive converters. You needed to spend a lot of money on equipment and converters to fully realize the sound quality benefits. But the average person doesn't want to spend lots of money for insignificant gains.
Even the computer enthusiast is asking him/herself, why bother with upgrading to Socket 939, PCI-e, SATA2, or 64-bit computing, when the price is high, and the benefits non-existent until some future undetermined date? Perhaps SLI will draw some people into the current equation. But until Windows x86-64 officially arrives, I bet they won't move many Athlon 64s. In all fairness, AMD met almost all their deadlines, and many moons later Microsoft failed to deliver on their promise.
Btw, I'm hearing rumors that this week AMD will be introducing 90mm chips to replace their higher end S939 130nm chips. These new 90nm chips, or San Diego and Venice, will be 15-20% more power efficient, and SSE3 instructions will be included. So maybe this is what AMD needs to jumpstart sluggish sales, especially since they are about to announce significantly lower profits from last quarter.