Arnold Schwarzenegger and Maria Shriver have yet to make their divorce official, even though they've already worked out an even split of their $400 million fortune. And according to TMZ, there are two possible reasons.

The first -- and frankly, more likely -- possibility is that it just doesn't matter that much. Since they already know how things are going to work out, and since they're so rich that there will be zero impact on their daily lives, there's just no rush. They'll get around to it when they do.

The other scenario is that they're leaving open the chance for a reconciliation. But once source says that's a lot less likely because Arnold has a girlfriend right now.

Either way, they looked quite the happy family last weekend at daughter Christina's graduation.