We doubt Intel really expected its Thunderbolt technology to prance in, completely obliterate USB 3.0 and sit on the throne of the Big Cheese. We also doubt that Intel thought things would go as poorly as they did.
Thunderbolt didn't fade into nothing, by any means. Apple made sure of that.
Still, the rest of the PC market is, even now, showing little signs of welcoming the technology.
One reason is that Thunderbolt is far from a necessary feature of a PC.
Price is also a problem. A controller chip sells for US$20 / 16 Euro, when a USB 3.0 controller chips goes for US$0.50-0.80 (0.39-0.62 Euro). Since Thunderbolt only offers twice the performance of USB 3.0, the difference is too big.
Things may change over the next two years, especially if Intel scales the performance of its invention, but costs need to drop first.