One of the many reasons why I tell people not to jump on the first bandwagon to come through town.
You always know when something new is released, within a couple of weeks something better will be released, or what was released in the first place will be dropped and replaced with something else.
Don't know how to answer your question though megadeth besides my thoughts on why people shouldn't have bought the AMD64's when they were first released.
I figure whether it be AMD or Intel occasionally have to release a couple versions of the same thing I guess to see which one proves better as far as performance, architecture, technology, heat, factors of that nature.
But yeah in all honesty it's stupid that they release socket 754 which doesn't support dual channel, socket 940 which requires only ECC and registered RAM, that basically by default leaves 939 as the best option in the first place.....so like you said...why bother with 754 when 939 seemed to always be the best choice.