Willing to spend $300+ on a fancy motherboard just so you can get USB 3.0 support? Yeah, that might not be such a good idea, if only because Intel is in no hurry to integrate the spec into its chipsets. That means companies have to go out of their way to offer USB 3.0 on their systems. The odds of seeing USB 3.0 on a cheap-o netbook, then, are pretty much non-existent.
You can probably guess why this is happening: how many applications or devices really need the 5Gb/s speed offered by USB 3.0? Your printer and scanner don’t, and neither does your Flip. How much bandwidth does the typical USB mouse need? I’m going to guess not anywhere near 5Gb/s.
So if there’s no “mainstream” demand for it, then why would Intel et al. goes out of its way to offer it? USB 2.0 is “good enough” for most people, and if Apple has taught us anything in the past 10 years it’s that people are fine with “good enough” products.
This isn’t to say that USB 3.0 doesn’t have its uses. What if you spend all weekend shooting HD video for your student project, and don’t want to sit there all day while you offload the files onto your hard drive? You could save a few minutes there with USB 3.0 I suspect. (Are there even USB 3.0 video cameras yet? I have no idea.)
I imagine that as more and more people have USB 3.0 support, more and more companies will be all, “Cool, let’s release Product With USB 3.0 now!”
Chicken and egg, I suppose.