That video review is really what I was thinking - it's great potential, but Apple being Apple, they refuse to do things that would make use of that potential. He mentions that it would be cool to use the iPad as an HDMI screen, which would be amazing but when will Apple ever support something as retro and uncool as a cable? They'd rather you just play Candy Crush XXL and never do anything useful than to give you such an ugly, horrible option.
And if it can export 4K video that quickly, why the hell can't it edit RAW images, like, at all? This would have been a crazy request 2 years ago, but now they've added the "Pro" suffix to it and it has a big screen and a stylus. In fact, a stylus is no use for video editing, but it's great for photo retouching. To me this screams "The iPad Pro is the ideal tool for photographers or people who work with images!". Use the iPad as an auxiliary display for your SLR in live view! Use it as a 2nd monitor for your Mac! Use it to do basic edits on your RAW images while on the go! Do some quick retouching, cloning, healing, with the pencil! I mean just what Lightroom can do. Not asking for full-blown Photoshop.
And yet no, not only are there no useful photo editing apps for the iPad, (Adobe basically released some crap light version of the light version of Lightroom which itself is a light version of Photoshop that edits the contrast of JPEGs), but even if there was a decent photo editing app, what the hell would you do with those files? Where would you even store a 2 TB library of images? It can't even connect to a USB hard drive! Because that would require cables, huh. Oh, wait, iCloud! Sure! Try downloading and uploading gigabytes a day! Just to save yourself from the horror of having to use a cable!
This is great hardware that is ahead of its software. By the time software catches up, the hardware will be obsolete. For now, it's just a big ass iPad with a stylus you can use to draw stuff.
Edit: Oh and wow, imagine using this as a Wacom Cintiq. A Retina display thin as an iPad without having to connect 2 cables to it like the Cintiq (one for power, one for display). The Cintiq is clunky, huge, and has a crap display with crap parallax. It has a plastic screen. The iPad would just be better in every way. But hey that won't ever happen I bet.