IMO, what's so great about the Amazon Kindle is the concept that they've integrated EVDO service into the device cost. This completely blows my mind. A wireless device, on a 3G cell network, and you've got no monthly or yearly service subscription.
Now, it's not like the Kindle has a browser, or an email client (although it looks like you can somehow email documents to yourself, but I imagine you email it to the Amazon Kindle site and download from there). I'm leaving the blogs out, because you DO have to pay monthly ($.99 per month if you're freaking crazy) to subscribe. But there's a handful of other devices that already have restricted internet-capable applications, and could really truly benefit from the wireless service.
Are we going to see the next generation of iPods or Zunes with 3G wireless capability and the cost of wireless service baked in? How about the next Sony PSP, Nintendo DS?
I think it will be interesting to see how this pans out. If it succeeds, we may start to see more and more devices with built-in wireless service, and less and less restrictions on what you can do with it.