Core i7 is a remarkable CPU. Intel has really outdone itself on the Core series of CPU and not one has been a disappointment. Each time Intel has an iteration of it, there is more power and more features to surface.
Core i7, while sharing the Core name is a whole different animal; fast, feature packed and designed for a totally new platform, making it Intel's big jump away from familiarization.
One of the biggest things that everyone has been looking forward to with Core i7 was the removal of the aging and antiquated FSB, allowing the CPU to finally live up to its potential. And the integration of the memory controller onto the CPU was the biggest leap forward in performance of all. However, Intel really didn't need to worry about a triple channel memory controller at this stage.
We have seen today that dual channel memory on the Core i7 is more than enough to keep it fed with bandwidth, especially since the CPU and memory are communicating with each other directly. There is very little lost bandwidth and it makes better use of all of the dual channel memory than the triple channel memory. However, with Intel's plans to increase speeds and allow heavier memory usage, especially with IGP based systems, the extra bandwidth will end up being welcomed.
Our moral to this story is if you're planning on a Core i7 system, don't just go out and buy triple channel memory straight away. If your budget allows for it, then by all means more memory will help, especially in Vista. However, with today's results you can see that dual channel memory is more than capable of keeping up with the Core i7.