Author and professor Tony Campolo speaks on the topic of God's omnipotence:
All the sin and suffering that have marked human history since Eden are the result of God relinquishing control over what we do. People like you and me abuse our God-given freedom and thus increase the hurt and destruction that is in the world.
To all of this, most readers will say, "We agree!" Yet, when I dare to say that God is no longer in total control over this world, so many of my fellow Christians go ballistic. They refuse to stop and think. If they did, they would realize that God must be self-limited if we are to come of age and become fully human. Without God choosing to be limited, we could not love God, because love is something that must be freely chosen-nor could we freely choose to love each other. And love is what is ultimately important.
I'm not sure what Campolo means by "no longer in total control." If he means that God has granted man a measure of autonomy to run things as he will then I think he's right. God doesn't directly cause every event or every decision that is made on earth.
If, however, he means that God could not change things even if He wanted to then I think he's wrong. In any case, there's more at the link.