I hate to be the voice of reason here, but how exactly does Gruber confirm or deny anything involving the new MBPs? He's reading the Engadget article and giving his take on their statements in a detailed fashion. This same Engadget article, has the exact same photos as people here were claiming to be fakes not even three hours ago. I actually read that DF piece before it showed up here, and it was just like any other DF article where Gruber speculates on something -- just that, speculation.
Just because he didn't write "I think" before every sentence doesn't mean he has one of the new machines on his desk and can confirm anything he's saying as true. He's just giving his opinion. When writing in an active tone of voice stating opinions as though they are facts is entirely normal. Especially when you're writing about somehthing rather sensational or trying to really grab your reader's attention. His opinions are well based in the way things have been heading, but let's remember John Gruber is a blog writer, a professional blog writer, but still a journalist who is really in the same position as the rest of us when it comes to information. If he was one of those priviaged few journalists who actually gets new hardware pre-release (like David Pogue or Mossburg) he would be under an NDA, just like they always are, and unable to actually give any info as fact before launch.
John Gruber's opinions are very good, and often times correct, but he holds no special source that gives him the ability to actually state whether a rumor is true or not anymore than Kevin Rose or 9to5 Mac can. All that is happening right now is a bunch of Blog writers are posting the same photos and roughly the same rumors, and then pointing at each other as their source of "confirmation". For all you guys know the same "source" is going to every rumor website under a differnet name and telling a slightly different story. This is the internet after all. Is that "worker in an obscure Pacific Rim component supplier" or "inside source in Cupertino" really in the Orient or California as they claim?