I would agree that a court would look at the assets in their entirety to determine what is fair - and that would seem to be the value of the business. Have a look at the LawAnswers Family Law Forum thread "Property Settlement - Divorce" which links to information relevant to your question.
Yes, the court would look at how much the business is worth (i.e. if you were to sell it at a particular time) and multiply this by your share in the company. This would be a rough estimate starting point.