Checking CNN.com and this story appears at a little after 9pm:

A senior U.S. official tells CNN Osama bin Laden was killed by the U.S. forces in a mansion outside the Pakistani capital of Islamabad. President Obama will address the nation regarding bin Laden's death.

Sources: Osama bin Laden is dead

And over at FoxNews.com they have this story as the top story:

Sources said bin Laden was killed by a U.S. bomb a week ago. The U.S. had been waiting for the results of a DNA test to confirm his identity.

We'll keep you updated as we find out more.