I don't think the low carb thing is going to go away soon. Whatever you think of it for weight loss, it is undeniably the fastest, easiest way to improve your blood lipid levels and to stabilize blood sugar problems, at least for a lot of people.
With all the Type II diabetics around I'll bet it just goes from fad to lifestyle.
Low carb dieting isn't going away, though it can't be expected to continue to enjoy the insane popularity it's had lately. The Atkins craze has established it as a viable (and arguably a much easier) alternative to low-fat diets. Pass the meat 'n' cheese.