Much has been made of the 'Stack and Tilt' swing this year. Mike Weir is a big believer of this motion. Personally I feel that the description of the concepts have been over exaggerated to help players develop the feel for the movement. Over exaggeration of the movement is a common teaching technique to help players feel the movement they are trying to create.
If you are trying to create better balance and consistency with your golf swing then watch Mike Weir's swing. Pay attention to his left leg during his backswing. His leg stays in exactly the same position as it is at address. His left hip will rotate back, but his leg stays virtually the same as the start.
Many players create movement by getting their back leg out of position. this creates side to side movement. That motion is hard to create consistent contact.
The other great thing to watch in Mike Weir's game is his swing rehearsal. He always makes a half back swing before he sets to hit his shot. No matter what swing he has been using, he has almost always had this routine. He tried changing it for a while, but quickly brought it back when it hurt his game. It is a great concept to copy, particularly if you are trying to change something in your backswing. The rehearsal let's you get a feel for the move you are trying to make before you pull the trigger for your shot.