1) For adult CPR, they are no longer having you switch to 15 compressions 2 breaths for 2-rescuer CPR. The ratio is 30:2 whether you have one or two rescuer. Part of the reason is to reduce confusion, and the other part is that they have discovered that continued compressions delivering consistent 25% perfusion to the brain is more important to survival than any other variable. Thus there is overall a strong new emphasis on continuing compressions with minimal interruption for any reason. On a child or infant you still switch to 15:2 for 2-rescuer CPR.
2) It is no longer recommended that you stop to check for a pulse every 2 minutes or so. You are not supposed to stop unless they start showing signs of life. You are supposed to continue compressions while pads for the AED (defibrillator) are being applied to the chest.
3) The hand position for compressions is now described as the center of the sternum, approximately at the nipple line, instead of being two fingers up the sternum from the xyphoid.
4) We were instructed on how to apply cricoid pressure to prevent regurgitation.
5) For infant CPR they are no longer recommending the two finger compressions. Now they want you to pick up the baby and put both thumbs on their sternum, holding them around the rib cage with you fingers. (They still have you doing the back slaps and two finger compressions in the case of choking.)
Those are the major changes since the last time I recerted. They're teaching the use of the AED to everyone, and the Heimlich maneuver and rescue breathing are not notably changed.