Yes, once filed with the court, Michael Jackson's will became a public document. Here is a link to the will, which I found on a law professor's blog that I monitor. It is a mere 5 pages, transferring assets into a trust and nominating his mother as the guardian to his minor children; the back up guardian is Diana Ross.
An icon of the music world, but his will is simple at to the point. Naming an executor, distributing his property, and nominating guardians for minor children. His will really is no different than the typical American.