Rumors about pop superstar Britney Spears joining Simon Cowell's "X-Factor" show as a judge have been circulating for months, but the singer is reportedly finally closing in on a $15 million deal to join the cast.  The debut season of Cowell's show on American television ended with two of the four judges, former Pussycat Doll Nicole Scherzinger and Paula Abdul, being removed.  Steve Jones was also let go as the host.  Spears will join Cowell and L.A. Reid as a judge, along with one other as-yet-undetermined judge.  No word on who the new host will be.