If I were Nintendo, I would launch a program about 6 months after the initial release. The program would include a shipping of 2 new colors every 2 months for a year. Towards the end of that fiscal year, I would launch a special 2 month "get everyone wanting a DS" program, where the triforce, nes, mario, and any other special addition DS's come out (about 6-7 different DS's in those two months).
Also, Ian, you wondered why the give the late adopters the best stuff? Well, simply, they are the ones that are the hardest to bring to your side. So, you need some sort of incentive to get them to buy the product. Price drops, pack-in specials, and different colors are all ways to attract the hardest group of customers. They screw over the early adopters becuase they know that they will by it anyways, even with a special addition or pack-in special. Except this time they did give them the Metriod Demo, which is a good start.