Golfbum, good point. Consider also that when the K8's memory controller is improved for faster memory that it also continues to support old memory. So, with an Intel northbridge implementation, if the new one is delayed then they continue to ship with another chipset running slower memory - vs. shipping a processor qualified to run with the same older memory.
After all, your point covers the new, bleeding edge chipset. By the time high-speed 3rd party alternatives are available the original chipset will have been fixed by Intel, or the memory controller will have been fixed by AMD.
The more we think through this topic, the more it seems that both approaches have the same set of fallbacks since slower, more available memory can be used in either case.