A Last-Case Scenario

Judgment Day has finally arrived for Joseph A. Wapner: After 12 years on the air, The People's Court was sentenced on Nov. 13 to cancellation (taping of new episodes will end in April). ''The producers decided that they could make just as much money showing reruns,'' says the stunned TV jurist. ''I just got the news yesterday — it still hasn't sunk in yet.''

Wapner, 73, has presided over 4,600 real-life small-claims cases (merchandise complaints, shrubbery disputes, that sort of thing) in his remarkable 2,300-episode tenure on the ''reality'' courtroom series, but he says the bench has never bored him. ''People treat me like a celebrity,'' he says. ''They want autographs, but they also show me a great deal of respect. I love doing the show.'' His favorite case: ''We had a 17-year-old girl sue her grandmother for a hope chest she had been promised for Christmas. I got them to settle out of court. It's the only time in 12 years I didn't have to make a ruling.''

Wapner's plans? ''I haven't had time to think about it, but I've pretty much ruled out a Supreme Court nomination'' (he's pro-choice, anti-school prayer, and believes the death penalty ''makes the state stoop to the level of the murderer'' — in case anybody in the Clinton Administration is listening). There is one job he is interested in, however: baseball commissioner. ''If they're looking for a good retired judge who's honest, I'm available.''