The general rule of thumb is that 50%-55% of the box office goes to the studio. The specifics vary from movie to movie, theater to theater and even week to week. Generally, the studio will take a bigger cut in the first couple of weeks than later, and the bigger the film is supposed to be, the larger the studio cut as well. The theaters get a much larger cut after the film opens and often renegotiate the contract if a movie fails to live up to its expectations. The theaters also get studio funding for ads, in theater posters and such like those millions of Tomb Raider drink cups in theaters coast-to-coast.
Back end deals can also affect the studios take. To keep the initial budgets down, several people involved with Pearl Harbor agreed to lower salary in exchange for a percentage of the revenue that the movie would bring in. Again, these are complex deals. But rumors say that about 10%-15% of the revenue from Pearl will find its way to various talent and associated companies.
My guess is that Disney will end up with about 45% of the box office take (give or take a few million). And Disney will NEVER publish the actual figure because this kind of information is Hollywoods best kept secrets. A whole sub-species of lawyers exist to do nothing but dig around studio financials and most of the time they find nothing.
In short, its going to be a hard fit to get Pearl Harbor to profitability.
P.S. The Cubs? How come you guys aren't pulling for Disney's California Angels? Oh that's right, the initials 'DCA' mean "bad" in all kinds of endeavors.