Again, I think there is more than a little truth in that in the lower level P&S and entry level DSLR markets, but I believe the majority of folks buying a $3K DSLR body understand the real comparative performance benefits of these cameras before they purchase, and while I think it's true that there is a natural inclination in folks assuming more MP is "better", if actual tests indicate conclusively that this is NOT the case, due to OTHER performance factors, then the MP count will become a virtual non-entity.
I agree in general, but I was in a photography seminar earlier last year, only weeks after I got my 60D, and even with my relative lack of knowledge at the time, I was appalled by how little understanding of their cameras most of the others in the class had. There were a few 7D's, a couple of D7000's, a couple of 5D's and a few other models. While the bodies were all below the $3000 mark, they were, for the most part, pro and semi-pro models, some with L lenses, and most of their owners could barely turn them on, and were generally shooting entirely in auto. I suspect that many well healed folks with little knowledge, or real interest, in photography will be buying the D800 as a "trophy" camera. To them megapixels will matter.
Unfortunately if there is a turf war for the hearts and minds of customers ans its perceived that MPs are the key to success, it won't matter if a superior sensor can be produced with fewer MPs.