Originally Posted by SeaWolf
I'd agree that one of the major selling points of the Kindle is that the network is (nearly) always there and always on. But if they're going to take the device international then having to negotiate separate telco deals (and hardware on different frequencies and protocols) in every country is going to be a serious hobble for it. The WiFi would be a compromise. It's not ideal, but better than having to connect to a PC and do everything there.
I do, from time to time, travel to from the UK to mainland Europe. I'd be very nervous of what the data roaming charges could accidentally result it (okay, so I've no idea how data roaming works in the mobile world, but I'm sure I've heard of rather unpleasant bills....). Although I hope that Amazon would pick up the tab, I still think it could be a nasty cost. Using Whispernet helps them avoid the roaming issues (I think!).
Also, I guess that there are regional rights/censorship/legal issues that will allow some books/newspapers/magazines to be sold in some countries and not in others -- how that is solved with true roaming I have no idea.