Thunderbolt peripherals are on the rise, but until the port becomes a standard feature on consumer grade PCs, its not going to be prevalent. It is a niche tool, and if you don't want it, its likely you don't need it. If you are a video pro, transferring large video archives frequently, or in my case, an IT pro who uses external storage for machine images >30gb ea, Thunderbolt becomes a very attractive option. FWIW my expectations for USB 3.0 were high, but I cant image a machine from a USB 3.0 device without consistency errors, which I could do on USB 2.0 no problem.
A quick newegg search shows cheap USB 3.0 on-sale at $60 ("normally" $80), while the cheapest TB drive is $160, so more than double. As I said, my experience with USB 3.0 for robust external storage has been less than favorable. You determine your own needs, but search Toms for reviews and benchmarks on TB storage and the data is consistently promising. More-so than USB3.o, and the less common eSata.
No doubt average consumers, Performance gamers, etc aren't in a hurry to get something they dont need. Industry pros dealing in sizable data chunks that need to be portable however are "all ears."