You may have heard, darlings, that Pat Buchanan's wriggled out of the WRC radio Braden-Buchanan chatter show. You'll never guess who they've hooked on the air to slide into his Rather Rightish Role: Phyllis Schlafly, foe of the Feministas. Phyllis ankles in as a Guest Host tomorrow and Tuesday evenings. "Just auditioning at this point," whispers a Station Biggie . . . And Supreme Courter Sandra Day O'Connor's abandoning the Wonderful Ones of Watergate, Ear glumly hears. She's buying at the Sanford, instead. (Surely you know the Sanford? Luxe California Street condo? Glossy little Dossier mag starred it in a spread last month?) Other Femmes Formidables who own there include the fair Diane Sawyer and former Carter speechifier Caryl Connor, who's already getting the Justice's mail. The new, four-bedroom Chez O'Connor was on the market for $375,000. Ear's too polite to ask for the Final Numbers . . . And Betty Beale, doyenne of Scribes of the Glittering Round, is toiling for spanking new Courier Diplomatique mag. (This, darlings, will leap from the still-glowing embers of the doomed Embassy News, very soon) . . . And Ymelda Dixon, another feisty social fixture, cloisters herself each morn to toil on her Book. It's a memoir-packed roman a clef that sends her into fits of giggles that frighten the neighbors. Watch out.