We've had some informative threads on this topic in the past, including links to other info, if you're interested in reading more about compression-only CPR. In the CEPA (sort of like CERT) program I just recently participated in, we had an AHA CPR segment and we were taught the latest 30:2 compression:breaths ratio from the 2005 guidelines. But those guidelines have been modified again not too long ago, so relatively soon, you'll likely see compression-only being taught as the most basic form of CPR. But it depends how quickly that will happen. It costs additional money to implement every time there is any change in the guidelines.

However, it's important to note that compression-only CPR is not really one-size-fits-all. For adults, situations like drownings, intoxication, choking, drug overdoses, etc. rescue breaths would still be recommended, and so would most pediatric situations. So, practicing rescue breathing would still be useful because compression-only works best in situations where the heart stops first, so there is still oxygen in the blood but no way to circulate, versus those situations I just listed, where generally the blood oxygen becomes depleted to the point where the heart then stops beating, so the thinking is that just circulating deoxygenated blood isn't so helpful and rescue breaths become more crucial.