I came across this article
from Men's Health today. It's six pages long, but it's easy to miss the link to the next page so be careful.
Basically it is kind of a review of the studies that people have cited to "prove" that increasing the saturated fat in your diet leads to heart disease. Their claim is that none of the studies actually proves this as a fact. One counterexample they provide is the Masai tribe of Kenya, in which the traditional diet is almost entirely red meat, whole milk, and cow's blood. These people were found to have a very low rate of heart disease despite the large percentage of their calories that came from saturated fat. Another claim in the article is that while saturated fat has been shown to increase LDL (bad) cholesterol, it has also been shown to increase HDL (good) cholesterol just as much if not more, and since HDL basically removes LDL from your arteries, there is no net increase in arterial plaque.
Really what the article seems to be saying is what we already know -- if you are not overweight, and you get lots of exercise, your chances of heart disease are reduced. You could eat 0% saturated fat, but if you are obese and never exercise, you might still have a cholesterol problem. You can be like the Masai tribe and eat a diet of whole milk and red meat, but if you're spending your entire life as a nomad working a cattle herd, you're probably getting enough exercise to counteract any negative effects of your diet.