Following the long show-biz tradition of bombshells marrying nebbishes (remember Paulina Porizkova and Ric Ocasek?), Julia Roberts wed singer Lyle Lovett last week in near-total secrecy. Herewith a few juicy details for inquiring minds: Why did the most glamorous celeb wedding since Beatty and Bening's take place in Marion, Ind.? Because Lovett's tour-bus driver is a member of the St. James Lutheran Church congregation in Marion. How did they clear the necessary bureaucratic hurdles? Roberts brought her passport, a birth certificate, and proof of rubella vaccine; Lovett brought tickets to his concert that night for county clerk Karen Bostic Weaver and her family. Didn't Roberts reuse the dress left over from her planned wedding to Kiefer Sutherland? No, the gown from those aborted nuptials is still gathering dust at designer Richard Tyler's Los Angeles store; they are keeping it for the ''archives.'' Where was the reception? | At the Deer Creek Outdoor Amphitheater where Lovett was performing. Bridesmaid Susan Sarandon and Tim Robbins skipped the party, however, opting for dinner at McDonald's South in Marion. They ordered a Value Meal for themselves and a Happy Meal for their son, Jack Henry, 4, who served as ring bearer during the ceremony. Whose hopes have been crushed? Presumably, Julia's exes': Liam Neeson, Dylan McDermott, Kiefer Sutherland, Jason Patric, and Daniel Day-Lewis. Will it last? ''I don't see it lasting more than six months or a year,'' says Linda Georgian from the Psychic Friends Network. ''Eventually, when she is in her 40s, I do see a marriage lasting, but I see other people between now and then.''