Q: Why not an iPad?
A: Because they are two entirely different things. It's not just the price point, it's the intended usage. The iPad is a multitasker, the Kindle is an eBook reader, plain and simple.
Q: Do you have to buy all your eBooks from Amazon?
A: Nope. You can get your eBooks from other sources (wink wink) and transfer them to your Kindle via USB or wirelessly through e-mail - once registered, an e-mail address will be assigned to your device, and you can send eBooks to this address as attachments and your device will download them wirelessly through WiFi or 3G.
Q: Can the Kindle understand PDF or MS Word documents?
A: Yes. However, I find it better to convert these documents to the Amazon eBook format (AZW) for better readability. Amazon actually offers a free conversion service - just e-mail the document to your Kindle and put "Convert" in the subject and it will be converted before reaching your device.
Q: Do I need a SIM card for the Kindle 3G? Will I get charged for the data access?
A: No. There is no slot for a SIM card, but presumably there is one inside the device that is already pre-configured for 3G access. Actually you can also use GPRS/EDGE if 3G is not available. And Amazon pays for the data access, unless you use 3G to download personal documents (i.e. the ones you send via e-mail).
Q: Will 3G access work in other countries apart from the US?
A: It works in most countries, but you can check the 3G coverage area here. If you have a Kindle and you want to see the wireless network providers within range, you can go to the Settings page and press Alt+EQQ.
Q: Can I use the web browser over 3G for free?
A: Oh, the heartbreak. I used to be able to surf the net over 3G for free. It's not a feature I abused, because quite frankly the experimental web browser sucks. But it was nice to have on emergencies, like when I really have to check my mail or when I am lost and in need of directions.
But now apparently Amazon has discontinued the free web browsing over 3G.
Due to local restrictions, web browsing is not available for all countries.The only sites I can access via 3G are Amazon and Wikipedia. Which, in the context of the world wide web, is almost equivalent to nothing.
So whereas a week ago I would pay 50 dollars more for a Kindle 3G (with unlimited *emergency* data access), it doesn't make sense anymore, unless you have absolutely no WiFi access.
Dammit, Amazon, I was rooting for you.
Having said that, I still think the 99-dollar Kindle WiFi is so totally worth it.