I noted several comments to the negative that the DX doesn’t have touch capability. I know folks are always enthralled by the “newest” thing but people have to think about whether the feature actually adds to the experience.
Personally I have two Kindle Keyboard 3G readers. First the keyboard UI is up to the 4th generation and is very mature. The touch UI is first generation and it shows with a lot of non-intuitive gestures. Second, the eink screens were never designed to be repeatedly touched so I’m not so sure it’s a good idea to be pushing on it both for long term reliability and general cleanliness of the screen. Third, the touch is enabled via IR lights on the borders which are blocked upon “touching” the screen which triggers an action. This is bad as the IR lights will continue to shine and drain the battery while you are reading (per the Eink manufacturer) whereas non-touch eink screens are “off” while reading. Additionally, ANYTHING that blocks the IR light will trigger the screen, a cover, being placed in a book bag, a drop of water, etc. Look away and you could be 30 pages from where you were. Fourth, I think the keyboard adds an ergonomic border to the bottom edge for easier holding and which moves the screen up slightly for better viewing.
Apart from the whole touch technology, the new Touch Kindles have two other defects. First, the power button is on the bottom and can easily be accidentally triggered. Second, the 3G is limited to browsing Amazon so no more free 3G email access overseas.
The main reason Amazon added touch was to simplify international distribution of the Kindle. A hardware keyboard requires hardware localization by region and really messes up inventory and forecasting. Touch Kindles only require a software tweak hence it has already been released in Italy and Spain with more countries on the way soon.
So ultimately Amazon made a change to simplify their operations and international sales, not to improve the experience for customers. In this case, “new” does not necessarily mean “better.”