There's still a segment of the population that likes to actually touch a product--and play around with it--before they buy it, and unlike Apple or Barnes & Noble, Amazon doesn't have any brick and mortar stores. However, as it did with the Kindle 3, Best Buy will carry and sell the new Kindles, so you'll be able to try before you buy.
It's worth noting that those new Kindles will only be available for purchase in-store. So far, the just-released $79
In other Kindle news, the Kindle Touch 3G, which starts at $149, won't allow Web surfing (outside of Wikipedia) over 3G, only Wi-Fi.
While we can't confirm what deals Amazon has in place with carriers, sources suggest Amazon probably pays a small fee per kilobyte downloaded rather than a set fee per device sold (once you pay for a Kindle 3G, the 3G service is free). We assume that Amazon is concerned that more people will use the built-in browser--and incur additional data costs--if their Kindle has a touch interface, which makes inputting URLs and clinking links easier.