Just received Irredeemable Volume 1 in the mail today, and have already read it twice. Couldn't be more excited about it. This is one of the scariest stories I've read.
The premise is that The Plutonian, a Superman-analog hero (anything you can do, he can do better) has gone rogue for some reason and no one seems able to stop him. The story really drives home the fear involved: what do you do when someone super strong, super fast, and able to hear a pin drop from ten miles is out to get you? He doesn't really need the death ray eyes, but they don't subtract from the terror.
Add to that the fact that this version of Superman hasn't let anyone discover his Kryptonite, and the fear ramps up.
By the time the story starts, the Plutonian is already a mass murderer who has leveled a city. A few heroes are left scrambling to stay alive long enough to learn how to stop him.
I knew a lot of this already, from reading volumes 1 and 2 of Incorruptible...which I also greatly enjoyed. Reading those stories, I had trouble believing that Waid could make a character who committed Plutonian's crimes into a believable person. But he has.
I'm going to be collecting Irredeemable now. I can hardly wait to get volume 2.