They raised the goalposts up five feet, made the recovery of a loose ball in the field of play reviewable (the "Navorro Bowman" rule) and voted to keep the game clock running after a QB sack outside of two minutes.
The league will also be experimenting with PATs in the first two weeks of preseason. Attempts in those games will be moved from the two to the 20 yard line. Two-point conversions will remain as is.
The NFL Competition Committee released it's statement on sportsmanship do's and dont's. (READ)