Is it a “gimmick” or the “next technological step”? The “functional equivalent of cable service” or the Sony Betamax? The “Super Bowl” of television copyright or “an overproduced” halftime show?

The U.S. Supreme Court on April 22 will sort through those ­charges and countercharges in American Broadcasting Cos. v. Aereo Inc. — what some observers have called the most important copyright challenge to reach the high court in a decade.