Ludacris revealed this week in an interview with Billboard.com that he should have his eighth studio album, Ludaversal," in stores by May.  The rapper revealed that his old pal Usher will appear on the record, and hinted that other stars are helping out on the set, as well.  Ludacris previously worked with Usher and Lil Jon on Usher's hit single, Yeah!," which held the top spot on the Billboard Hot 100 for twelve weeks in 2004.  Ludacris indicated that he's about 40 percent finished with "Ludaversal," and making fast progress.