See the quesabesde's first review on the K-r with some full size samples, from ISO 1600 to 25600 (different scenes, though) via Information on Digital Cameras (Japanese site).
Click on the Japanese link and you will have direct links to those sample images. No translation is actually required as everything is just self-explanatory. Just measurbate yourself to see how this "new" Sony 12M sensor performs (in the K-r)!