The article seems a little rambly, but I get that this is kind of part of Jon's style.
As for the art itself: not into it. Pretty comic-book-y. And that yuan-ti pureblood is
godawful. It's just begging to be
hawkeye'd. The marilith is a bit better, but she's still all "I'm gonna hold all these weapons out here at my side, jut out my bosom and bottom, and appeal to the Male Gaze a bit!"
Steve Prescott isn't winning me over with cartoons and T&A.
I've got some concerns about that "IP Bible." Part of what I think lead to 4e's sacred steak buffet - and all the ill will it generated - was the desire to cleave to the brand image and generate a holistic view of what "D&D" was to the extent that it came off as stridently ignoring what the players wanted it to be. So it makes me nervous. He does a pretty good job assuaging my fears.
I wonder why they shouldn't do a separate "IP Bible" for each setting. In FR, goblins look like X. In Greyhawk, Y. In Dragonlance, Z. In Birthright, Q. They can concern themselves mostly with the big brands (like FR and Dragonlance) and they don't need to be artificially tethered to these visions when they go work on what a goblin would look like in a gothic horror setting for when they do Ravenloft. I guess it'd be a lot of work.
I guess I just feel like the art should reflect the message that
this is a prop for you to use how you want, not a code to be adhered to. Which is probably naive of me.