I just had it happen to my 2005, and was able to figure it out before I found this. I was backing out of the driveway, and went to shift to drive, and it felt like the column shifter just broke loose, and freaked me out. Pushed the truck back into the driveway, shut off the engine, but couldn't get it to turn off completely, as it was stuck in ACC. First thought was that the transmission went out, but logic kicked in and made me realize the transmission would not make the shifter act like that. Took the covers off the steering column, moved the gear shifter, and saw the linkage just hanging as the shifter was moving. Same as other people, the plastic piece had shattered into a bunch of pieces. Got a zip tie, tightened it down as much as possible, and good to go.
Now I wonder how many people this has happened to, they get the truck towed to Nissan or wherever, and are then told it's a transmission issue, when in fact it's a .10 piece of plastic.