The Backstreet Boys' tyrannical reign atop the "Billboard" album chart may soon be over.Hollywood trade paper "Variety" reports that early industry buzz has the group's "Millennium" album being knocked out of the number one slot by the arrival of Limp Bizkit's "Significant Other." First week sales figures for the album won't be released until Wednesday, but "Variety" reports that industry estimates place Limp Bizkit's first week sales near 720,000. If the estimates turn out to be accurate, Limp Bizkit would wind up with one of the biggest debuts of the year and the number one album in the country. The Backstreet Boys have had a firm grasp on number one since "Millennium" was released five weeks ago. The album sold more than a million copies in its first week in stores and has sold close to three million copies since then. Whether the Boys or Bizkit winds up on top of the chart, the big winner of the week looks to be the Firm, the management company that handles both acts.