The darling of Melbourne theatre, Marina Prior, will return to the stage in a blockbuster musical.     Prior will star in The Witches of Eastwick -- the first musical at the renovated Her Majesty's Theatre.     She will join Good News Week host Paul McDermott who plays Daryl Van Horne, a role made famous by Jack Nicholson in the 1987 film.     Fellow witches will be Angela Toohey, who played Liza Minnelli in The Boy from Oz, and television and theatre actor Pippa Grandison.     A feature of the $12 million Cameron Mackintosh musical will be the three witches suspended by wire and flying out over the audience.     The musical completed its London run in October after 504 performances.     Actors Geraldine Turner and Tony Sheldon will have minor roles.     Industry sources said Prior is presently negotiating with Sydney's Ensemble Theatre to withdraw from her commitment next October to perform in Harp on the Willow.     Witches of Eastwick is expected to open in July for a three-month season, followed in November by Cabaret, starring Lisa McCune.  Contrary to reports, Toni Collette will not be in Cabaret.     Her Majesty's Theatre will open on May 8 with the Royal Shakespeare Company's The Hollow Crown.     The theatre aims to stage ballet, opera and drama as well as musicals.