Well, this had to happen eventually: someone from an Apple tablet partner—McGraw-Hill's Harold McGraw III—has confirmed the tablet's coming tomorrow, that it'll run an iPhone-style OS, that it's "terrific", and that he'll probably never work with Apple again.

MacRumors caught the slip during a CNBC segment, in which the anchor lobs a softball closer question about the—excuse me, a—tablet, from Apple, maybe. Instead of deflecting, Mr. McGraw just started talking about it as if it'd already been announced:

Yeah, Very exciting. Yes, they'll make their announcement tomorrow on this one. We have worked with Apple for quite a while. And the Tablet is going to be based on the iPhone operating system and so it will be transferable. So what you are going to be able to do now is we have a consortium of e-books. And we have 95% of all our materials that are in e-book format. So now with the tablet you're going to open up the higher education market, the professional market. The tablet is going to be just really terrific.

Holy hell, guy. So, now we know a few things about the tablet! It's real, it's going to have a wide media strategy that at the very least includes textbooks, and it may be exactly what we predicted it will be, and apparently it doesn't suck, according to this man in a suit who is heavily invested in its success, or at least was, until he barfed up his NDA all over CNBC's anchor table. We reached out to the company regarding the slip, they're not calling back.

Don't worry, McGraw-Hill guy, you'll still get a Christmas card from Steve this year. Just make sure to have it checked for anthrax. [MacRumors]