He succeeds Gordon B. Hinckley, who died Jan. 27 at 97, because Monson is the longest-serving member of the church's Quorum of Twelve Apostles.
That part is not a surprise.
What is still in question is who Monson will choose to elevate into the governing three-man First Presidency. The speculation has already begun about whom he will name at a news conference to take place in the Church Administration Building.
There is only one rule for choosing a member of the First Presidency: no women. Other than that, the choice is wide open, but selections tend toward men who already have proven their worth as church leaders. It's usually a lifetime position, so Mormon presidents are not willing to take many risks. Most counselors were apostles, a group of men whose place in the seniority is determined by the day they were appointed to the Quorum.
Monson was just 58 when he was called into the First Presidency following the death of Spencer W. Kimball in 1985, but he was third in the line of seniority, after Howard W. Hunter and Hinckley.
It would be highly unusual if he didn't retain Henry B. Eyring, second counselor under Hinckley. But the next three men in line - Boyd K. Packer, 83, L. Tom Perry, 85, and Russell M. Nelson, 83 - are all older than Monson, who is 80. He could pick Packer as a way of preparing him to be president someday. Some argue Monson should skip the first three apostles and pick Dallin H. Oaks, who is 75, reasoning that he is young enough to have a chance at the office.
But maybe Monson will move down in seniority a step further to M. Russell Ballard, 79, because they both were mission presidents in Toronto, are extroverts and reportedly are good friends.
A popular choice would be Jeffrey R. Holland, 66, a former president of Brigham Young University who spent two years in Chile learning how to manage rapid growth and the cultural challenges facing South American Mormons.
If he wants even more youthful energy in the presidency, Monson could tap David Bednar, who is 55. What Bednar, former president of BYU-Idaho, lacks in experience, he could make up in enthusiasm and good health. And if he wanted to send the message of a worldwide Mormon community, he could bring in the charismatic German apostle, Dieter Uchtdorf, 67. Monson may have a soft spot for Germans because he negotiated with government officials to build a temple in Freiberg, Germany, while it was behind the Iron Curtain.
However, the rules do not require Monson to choose a sitting apostle.
President Heber J. Grant, who governed from 1918 to 1945, sidestepped the church's hierarchy in his 1933 appointment of J. Reuben Clark as his second counselor. Although Clark, as U.S. ambassador to Mexico, was one of the church's most prominent members, he had not served a mission, nor had he ever been a bishop or stake president.
In that same vein, Monson could choose Bishop David Burton, the "presiding bishop," who has directed the church's renovation efforts in downtown Salt Lake City.
If he wanted to maintain a connection to the Democrats, he could tap Marlin Jensen, a member of the First Quorum of Seventy who serves as the LDS Church historian. Jensen, a lifelong Democrat, was among those who represented the church on the recent PBS documentary, "The Mormons."
For a total wild card, Monson could choose his fishing buddy, billionaire philanthropist Jon Huntsman Sr.
Monson is likely to name his counselor at the same time his own presidency is announced. If he does choose a counselor from the Quorum, that will create another opening among the Twelve. Then Mormons will begin a new round of guessing.
* PEGGY FLETCHER STACK can be contacted at email@example.com or 801-257-8725.