To me this is one of the saddest things a man of God would have to hear from God, "What I have told you to anoint has grieved my heart so much that I am not only going to take away his kingdom and give it to another but I am going to remove my anointing off his life."
Saul's disobedience had cause God to sigh in such a way that He could no longer tolerate allowing him to lead His people. A leader who fears the people and who listens to the people rather than the voice of God will always fall into compromise and that will lead to disobedience, no matter how you fix it up.
That word "repenteth" mean to "sigh." It is like you take a real deep breath and just release it, as someone who is in deep sorrow would do. Samuel "cried" unto the Lord all night. That isn't the cry of give Saul another chance. That word "cried" means to "shriek" (from anguish or danger). Samuel's cry was because God's heart had been broken. God already knew the outcome of setting Saul over His people but He wanted to show Israel their "own" heart.
Friend, let us not be half-hearted in our devotion to God or shallow in our obedience but lets burn with the passion of God for His will to be done on Earth as it is in Heaven.