The site, which was really macrumorslive.com was streaming instant text and pics of the keynote, when "Steve Jobs DIED" showed up as one of the posts.
Minutes later, the guys at MacRumors apologized and said that they didn't know how that post got in there. (see the 9:27 AM post in the pic)
Then, at 9:30 AM, the hackers again posted: "Oh, Wait, Sorry, Steve did die. Our condolences".
After that, the site began posting gibberish and other things that had nothing to do with the keynote address. That's when I knew the site was hacked. Here are only two screenshots I got of the hack before MacRumors.com went down:
If you can't see the full picture, ere are the direct links:
http://i42.tinypic.com/156g20y.jpg
http://i41.tinypic.com/34gopea.jpg
