But apparently cholesterol is a meaningful measure for risk of other diseases, such as Alzheimers (low HDL, high LDL are risk factors) and breast cancer (high HDL is preventative in obese women).

So what may be happening is that cholesterol isn't a useless concept re heart disease, but rather that there are different forms of heart disease, some cholesterol dependent and others, not. Just as cancer arises from many different sources and from many different processes.

I think it's healthy to be mildly skeptical of "received wisdom," but don't think it's time to throw the cholesterol concept out quite yet.