When the private life overwhelms the public persona - Is Tom Cruise about to become the next Mel Gibson?

I don't generally discuss gossip, so I'm going to do my best to keep this film-centric.  First and foremost, there is bitter irony that this is all occurring just as Tom Cruise has reaffirmed his movie stardom.  Seven years ago, his box office bankability was put in severe doubt due to the beginning of his courtship of Ms. Katie Holmes.  Now, just as Mission: Impossible - Ghost Protocol has reaffirmed both his box office muscle and his dedication to a certain level of mainstream quality, the end of this relationship may torpedo his career all over again, be it temporarily or permanently.  Now of course the film that Mr. Cruise was promoting back in June of 2005 when he performed his famous couch-jumping was Steven Spielberg's War of the Worlds, which went on to earn $234 million in the US and $591 million worldwide, making it Cruise's highest grossing film ever on both levels (M:I4 eclipsed it worldwide last year with $693 million).  In the years that followed, we had a somewhat under-performing franchise sequel (Mission: Impossible III with $133m domestic and $397m worldwide on a $160m budget), a political drama that was never going to be a blockbuster (Lions For Lambs, which earned $15 million in the US but $63 million worldwide on a $35 million budget), an over-budgeted but well-reviewed potboiler (Valkyrie, which cost $90 million and earned $200 million worldwide), and Knight and Day, a $117 million action comedy with Cameron Diaz that still earned $261 million worldwide.  So, coupled with a crowd-pleasing cameo in Tropic Thunder, the idea that Tom Cruise had lost his luster was more about public relations and alienating some of his more casual fans than any real loss of box office mojo.  But this may be different...