A K-r hands-on preview has been published at a Korean site, here it is (or the Google translated English page here).
There are illustrations for appearance (body, proprietary Lithium battery and the optional AA battery adaptor), menu operations, size/weight comparisons, frame rate and mirror/shutter action/sound videos and so on..! Nice!
Warning: The Korean site and page loading has been very slow. So, be patient if you really want to view! :-o
Tips for Playing Videos: Download the specific video clip first. The first time for playing back will not be smooth. After it has been saved and fully buffered, play again and you can see and hear the machine gun running smoothly! And, it looks that the mirror action of the K-r has been somehow improved (when compared to the K-x) - swifter and smoother but the force (and hence vibration) is still large, though! :-D