I have heard guys with the 08/09 steering update have DW after that mod is complete. It is not the tires IMO. I would check all the bushings, ball joints, tie rod ends and most importantly i would check the steering stabilizer.
JFYI Bilstein now makes a steering stabilizer for the Dodge.
Alot of guys think their ball joints are within spec but the minute you can feel the smallest amount of play they are toast. I was talking to a front end guy and he was telling me so many guys have no idea how to check the ball joints and think a little play is within spec. Not so.
I have been very luck and have never had the DW in 160,000 km so im sure i'm due since i suspect i have at least one ball joint that is toast.
My choice in ball joints are XRF, Dynatrac, and Carli. Carli is last since they are 1200-1300 bucks for a set. Dynatracs are around the 600 buck range, and XRF's are 370 bucks for a set.