Having been infuriated by a proclamation on HDTV which seemed predicated on a couple of pals at a party, I went in search of more rigorous information. Nothing is the final word, but I discovered this informed piece that seems both comprehensive and also provides much food for thought for marketers.
In the latter regard, it was point eight that really resonated. It echoes what I've suspected about many sectors. "Enthusiasts are getting tired (and smarter)......This leaves a shrunken market of even the bleeding-edge consumers, and that means even less sales to early-adopters". The Gap may want me to be on the bleeding edge of technology in order to buy some T shirts, but here is the suggestion that, even in a sector that is famed for them, the early adopters are not adopting as early as before.
Marketers must remember that they are both Joe Public and they are not. Yes, they are users of the products/services that they sell (and can thus get valuable, albeit subjective, insights into their customers' mindset), but they also get far more involved in the minutiae of those products/services than all but the rarest of customers. This is as it should be. No detail should be too small for the marketer, but increasingly it seems you also have to be able to identify with your inner apathist.