tmz.com:
We’ve just learned Michael Jackson has died. He was 50.
Michael suffered a cardiac arrest earlier this afternoon and paramedics were unable to revive him. We’re told when paramedics arrived Jackson had no pulse and they never got a pulse back.
Read the whole story: tmz.com

I realize it’s TMZ and that it’s a gossip rag, but they’re not usually wrong. And I’m sure they wouldn’t report something like this without some sort of confirmation.