merging from a self-imposed exile in which he was treated for an addiction to painkillers, Rush Limbaugh returned to the air today. And listeners who tuned in during the first few minutes of his radio show would have been forgiven if they thought they were hearing an Oprah-style self-help session. "I have to admit that I am powerless over this addiction that I have," Mr. Limbaugh, speaking from a Manhattan studio, told his listeners, just after noon on the East Coast. "I used to think I could beat it with force of will." During a 16-minute opening monologue, Mr. Limbaugh,...