The the most fantastic and extraordinary battle for Earth begins in this awesome book. Darkseid returns from the dead and threatens to destroy all reality. He has mastered the Anti-Life Equation and uses it to eradicate all free will. Superman, Batman and all of Earth's heroes rally together to stop him. Even some of Earth's villains, such as Lex Luthor, are so disgusted by Darkseid's plans that they form an alliance with the heroes.
Overall, this is a respectable series. It brings an end to the story of the New Gods and sets one of the most fantastic Batman stories in motion. And it punches Countdown to Final Crisis right in the gut, since one of the panel states "Don't worry about Countdown." Dear God, Countdown was awful.
The bad side is that some of Countdown's storylines are left hanging in FC, and this series has to pay the price by trying to pick up the pieces. Let's face it, Final Crisis didn't finish those threads, but Grant Morrison did his best in a satisfying way.
This basically marks an end to an era of the DC Universe and begins another.