HailMary -
agree with the rest of you that AMD can easily make changes to the on die memory controller as long as they have the resources to do so. They used to be able to leave most of this work to 3rd parties like Via and Nvidia, and now it all has to be in house. Has AMD invested enough in this area to ensure they are pursuing DDRII in a timely manner?
Actually, AMD always came out with the first memory controller (and it was usually the best one for at least 12 months) throughout the K7 line. It was produced as a reference controller and sold to insure there would be a solution for the motherboard makers.
Typically, Via would come out with the second memory controller, it would run a little faster and have bugs. One of the big reasons that K7 never made it big in the corporation!
So AMD already had the expertise in-house. In terms of motherboard reliability, K8 is miles ahead of K7, and corporations are taking it seriously. The chipset makers get to produce integrated peripheral controllers and everyone is happy.
Except Intel. :)
By the way - your point on turnaround time for a North Bridge memory controller vs. integrated is interesting. The chipset makers never did turn around those things as fast as they should, I think they had to work through inventory (for cost purposes, they have to do a huge run, and then sell their mistakes). So, in theory you are right, but theory has to meet practice at some point...