American Airlines charging for luggage

From the NYTimes.com: American, Cutting Back, Plans $15 Bag Fee

American Airlines, the nation’s largest air carrier, said Wednesday that it would begin charging $15 for many passengers to check their first bag, eliminating a free service that passengers in the United States have come to expect during the modern jet era.

I wonder how long it’ll take for the other airlines to follow suit?  If they do, it’ll just make flying coach that much more painful as everyone will try carrying on their bag on the plane.