I'll throw in my .02:
Link to a thread I started about this issue for those interested:
End result I got:
I took my truck into the dealer and told them I had a slipping clutch and that there was a TSB to resolve the issue. They checked it out for about 30 mins and came back and said they would fix it under TSB 0066-11.
Clutch Cover Assembly
Clutch Disk Assembly
Replacement parts are AISIN, NOT LUK! Truck feels like new, shifts better than it did when new.
This is a real pain in the Ass! Good luck to all you '12-'13 owners out there. Stay on 'em!