Estate tax pros are eagerly awaiting a Tax Court ruling on a celebrity case: The estate of Michael Jackson. The late singer’s estate disputes adjustments that IRS made to Form 706. The big issue is the value of his name and image at death. The difference between the parties on this amounts to hundreds of millions of dollars. The trial was held this past Feb., and a decision is expected sometime next year. Experts hope the ruling will provide a map for valuing estates of other deceased stars, such as Whitney Houston…which is already in the Tax Court pipeline…and Prince.