From the link:
The Kindle DX is the same size as the iPad. It has a black and white E-Ink screen, 4 gigabytes of internal storage, 3G access and costs $489. Meanwhile, the cheapest version of the iPad has a full-color touch screen, a powerful processor and graphics chip, 16 gigabytes of flash storage, Wi-Fi and sells for $499.
The cheaper iPad might not have 3G or the same battery life as the Kindle DX (up to 4 days), but on every other count it wins. It has both a gorgeous screen and vastly more functionality. And, while Amazon has established an excellent, easy way to buy books, iTunes, which already has some 125 million customers, will give it a run for its money.