Dude, how could Superman be dead?
He, uh, kinda doesn't exist, being that he's a fictional character an everything.
But I DO get what you're asking; is he "dead" in the continuity of the world of the DC Universe.
And the answer is no, he's not dead. He died, but since he is like DC's most recognized super hero (yeah, even more than Batman, surprising, no?) they pretty much had to bring him back. I mean, come on, Superman dead? Its just a bad idea. Too bad no one was there to tell that to the "geniuses" that came up with the idea of killing him in the first place.
So yeah, he's "alive' and well, and is just as powerful as he was before.