D&C 90

As Nephi taught his people, he tells us -

"...I did liken all scriptures unto us, that it might be for our profit and learning."  (Book of Mormon | 1 Nephi 19:23)

I feel the same way as I read this revelation.  In this revelation, the Prophet Joseph Smith, a president of the Church is told -

"...thou art blessed from henceforth that bear the keys of the kingdom given unto you..."  (Doctrine and Covenants | Section 90:2)

And of these keys -

"...the keys of this kingdom shall never be taken from you, while thou art in the world, neither in the world to come..."  (Doctrine and Covenants | Section 90:3)

Of priesthood keys, according to the Handbook of Instructions, Book 2, 2.1.1, we read -

"Priesthood keys are the authority God has given to priesthood leaders to direct, control, and govern the use of His priesthood on earth. The exercise of priesthood authority is governed by those who hold its keys (see D&C 65:2; 81:2; 124:123). Those who hold priesthood keys have the right to preside over and direct the Church within a jurisdiction."

In this revelation, we begin to understand the doctrine of presidencies as the Lord then instructs, the two counselors in the First Presidency -

"...verily I say unto thy brethren, Sidney Rigdon and Frederick G. Williams, their sins are forgiven them also, and they are accounted as equal with thee in holding the keys of this last kingdom..."  (Doctrine and Covenants | Section 90:6)

At first it may appear that these two counselors held priesthood keys, but in the same section of the Handbook of Instructions we read -

"Counselors to priesthood leaders do not receive keys. They are set apart and function in their callings by assignment and delegated authority."
Thus in my mind, "they are accounted as equal with thee in holding the keys", would suggest that a unified presidency also hold keys even though the president is the only individual that holds priesthood keys.

But what is important for our profit and learning is the counsel given to those that serve in the presidency -

"...now, verily I say unto you, I give unto you a commandment that you continue in the ministry and presidency...you shall from thenceforth preside over the affairs of the church and the school;
14 And from time to time, as shall be manifested by the Comforter, receive revelations to unfold the mysteries of the kingdom;
15 And set in order the churches, and study and learn, and become acquainted with all good books, and with languages, tongues, and people.
16 And this shall be your business and mission in all your lives, to preside in council, and set in order all the affairs of this church and kingdom.
17 Be not ashamed, neither confounded; but be admonished in all your high-mindedness and pride, for it bringeth a snare upon your souls.
18 Set in order your houses; keep slothfulness and uncleanness far from you.  (Doctrine and Covenants | Section 90:12 - 18)

There seems to be a strong warning in counsel given in verses 17 & 18 to those that preside...beware of high-mindness, pride, slothfulness, and uncleaness.  Absolutely critical to be guided by the Holy Ghost.