The Kindle Fire is the bestselling product across all of Amazon for 11 straight weeks now and Amazon is building millions more to keep up with demand. In addition to the seamless access to Amazon products and services, you can use the Kindle Fire as an Android tablet with Office document support through 3rd party apps. If I didn't have an HTC Flyer then I would have kept the Kindle Fire and eventually may end up going back to one since the media consumption experience is so easy with Amazon Video, Amazon Cloud Player, and more.
As you know, I am a firm believer in eInk devices for the absolute best ebook reading experience and the $79 Kindle is perfect for gifts this Christmas. I am partial to the new generation of touch screen eInk devices and the Kindle Touch and Touch 3G are available at a reasonable $99 and $149 too.