BMW has been working on a new generation of K-bike for a while, but there hasn't been a lot of info availble. Looks like that's starting to change a bit. From Motorcycle Online:

"Its all pretty radical. A 16V inline four designed for 1000-1300cc variants mounted across the frame is not exactly a novelty outside the BMW-Welt. However, starting with the hefty forward slant of the cylinders (60 degrees) and state of tune (160 to 170PS) things start getting pretty interesting..."

The above article has a comment that links to pictures of the new bike.