TV/RADIO

‘Cheers’ Reunion Set: Shelley Long will return as Sam’s old fling Diane for a final toast on “Cheers” before the NBC series closes its tab for good on May 20. “She will be coming back as a guest star for one of the final episodes, but not necessarily the finale,” a source at Paramount Television confirmed Tuesday. Diane Chambers was last seen at Cheers in 1987, when she said she was leaving to write a novel. Meanwhile, Long’s own comedy “Good Advice,” in which she plays a marriage counselor, is aiming for a CBS premiere in early April.