Reports of the death of the network miniseries have been greatly exaggerated. After this month's Lonesome Dove sequel and JFK epic, a slew of multi-night dramas will be hitting the airwaves. Among the biggies: * The Thorn birds: The Missing Years (ABC, six hours, unscheduled) Richard Chamberlain and Rachel Ward will reprise their 1983 roles as a priest and the Aussie babe he's smitten with. Will they make love again? ''It's what the public wants, isn't it?'' says producer David Wolper.
* The Sonny & Cher Story (Fox, four hours, unscheduled) Based on Sonny's 1992 autobiography; no cast yet, although Bono suggests, ''Kevin Costner could play me and Roseanne Arnold could play Cher.''
* The Stand (ABC, eight hours, May 1994): Molly Ringwald and Rob Lowe star in Stephen King's futuristic horror story. ''ABC said I could have 51/2 hours (eight with ads), so I jumped like a hungry trout,'' says King.
* Scarlett (CBS, eight hours, November 1994) The two-year search is finally over: Joanne Whalley-Kilmer (Storyville) gets to play the South's ''first feminist'' (as producer Robert Halmi Sr. calls her) in TV's Gone With the Wind sequel.
* The Menendez Trial (CBS, length not set, unscheduled, untitled) Edward James Olmos (Miami Vice) reportedly will play the murdered patriarch in America's latest favorite real-life melodrama. NBC and ABC are said to be on the case, too. Move over, Amy. -Benjamin Svetkey, Stacy Jenel Smith, and Bruce Fretts
