(--There are rumors going around that there's a second will. But we're hearing that's NOT true. Michael had made previous wills . . . but legally, his most recent will would supercede them.)

As we also heard, Michael's mother, KATHERINE JACKSON, was named the primary guardian of the kids.

But if Katherine were to die . . . or was unwilling or unable to act as guardian . . . Michael stipulated that the kids be handed over to DIANA ROSS. (???)

(It's not clear whether Michael ASKED Diana about this before naming her in his will. Obviously, it's customary . . . and more than a polite courtesy . . . to do so. But Michael never had a complete grasp on our human customs, did he???)

As for Michael's estate . . . the will lists its value at $500 million. But all of that is in, quote, "non-cash, non-liquid" assets . . . including the Sony / ATV music catalog and other, quote, "interests in various entities."

Michael willed that his estate be placed in the Michael Jackson Family Trust . . . which is administered by attorney John Branca and music executive John McClain. The beneficiaries of that trust are Michael's three children and his mother.

As expected, Michael gave nothing to his father or any of his eight siblings.

DEBBIE ROWE gets a mention in the will . . . but not a good one. The will states, quote, "I have intentionally omitted to provide for my former wife."

Michael provided for her quite handily in life. He most likely gave her MILLIONS to disappear from their kids' lives.

However, as the children's biological mother . . . (--we think) . . . Debbie would most certainly have rights, should she choose to exercise them. We STILL haven't heard whether she plans to do so.

As for Michael's estate being valued at $500 million . . . well, this will was drawn up seven years ago. It's probably worth a lot less . . . but it could still be worth a fortune, if it were liquidated and Michael's debts were paid off.

Katherine Jackson remains a "special administrator" of the estate. But Branca and McClain are requesting that they be placed in control, as stipulated in the will. A hearing on that matter will be held on Monday.

(It's not clear whether this will turn out to be a BATTLE. We don't know if Katherine Jackson will fight to remain in control of the estate. Some reports indicate that this is just a formality, and that everybody is pretty much on the same side here.)

Branca and McClain issued a statement saying, quote, "As we work to carry out Michael's instructions to safeguard both the future of his children as well as the remarkable legacy he left us as an artist we ask that all matters involving his estate be handled with the dignity and the respect that Michael and his family deserve."

Read the will here