He actually wrote something along the lines of "nearly certain"
But would someone explain why anyone at Apple would risk heir job, even their career, leaking this information only a day or two before the event?! They are anonymous, so they get no 15 minutes of fame. None of the "rags" involved are in the business of paying for leaks (as far as I know) and, even if they were, they don't have enough money to make it worthwhile to someone to risk their livelihood.
I'm also appalled by the ethics of the developer and the tech sites for publishing the information. Does it really get them that much more advertising revenue? At what cost to their integrity?! It's not as if these were State secrets or evidence of hidden collusion with a foreign government. Plus, it was all coming out in a couple of days, anyway.
At one level, they've done a disservice to the Mac community. Is their role to scoop Apple and pass along leaks? Or, is it to be there with deep analysis and insight?! They could have taken the information and used it to prep in- depth stories, in advance, and not spoil the surprise!