My ultimate prediction and thought on this is that it's a case of pointless innovation.
It's honestly Microsoft turning into Apple so hard they are getting a sore arse. I mean pointless touch interface, minimalist design, overpriced lump of rubbish with poor specs, and it's targeted to professional graphics designers? I mean they even copied the bloody apple logo on the back of the (Tablet?), something Apple has been doing for over a DECADE.
I don't go much graphics work, but I do do a lot of computer oriented work, and that looks more useless than something Apple would make. I doubt even serious graphics designers want that because they already have working professional tools in place that are probably cheaper and more effective than a 4000 dollar computer. The Wacom tabs are not that expensive for a good one, and if you're a serious cretin, I mean graphics designer, you will be using Apple anyways (since they have all the good friggin software, )
It's something Microsoft never made, never needed to make, and never should have made. I even bet you the stupid dial doesn't work.
Microsoft is trying way too hard to steal the "creative" market from Apple. They've been running TV commercials here in the US for the last few months that feature everything from college students (liberal arts majors) to broadway set designers gushing over how much better their Surface Pro is compared to their old MacBook, because they can draw on the screen...
In reality, they're comparing Apple's to, uh, well, not Apples! A better comparison would be a Surface Pro vs an iPad Pro, really.
I also know a few designer types who use (and love) a combination of of a MacBook Pro + iPad (with a third party pressure sensitive stylus). There's an app called Duet that lets you turn an iPad into a second monitor. There have been apps like this before, but they were traditionally laggy when run over WiFi; however Duet does it over USB, so there's no perceptible lag.
So essentially, your iPad becomes a portable Retina Screen + Tablet. Works great for everything from Photoshop/Illustrator to web design and coding. (I use my iPad mini as a third monitor for my MacBook Air when I need extra screen space. I drag a browser window over to it so I can view PDFs when doing board layouts.)
You know what else does that? A touch screen monitor! A feature Microsoft tried so dearly to implant into Windows 8 user's head. They made an entire touch screen operating system that would have done "Alright" on a mobile device where a touch screen makes sense, but I have only ever seen one touch screen monitor in my entire life. I am not joking. I think Microsoft just got sick of waiting for people to buy touchscreen monitors and decided to shove them down our faces outright.
And I can see why nobody wanted a touchscreen monitor. There have been light pens for YEARS, Wacom tablets, are already the tool of choice for the average graphics designer, and if they wanted a touch screen from drawing, they could get a touchscreen monitor and put it on a VESA monitor arm.
And another more on topic comment, a knob? Really? Just a dial. I understand the want for more physical controls, even though having tons of buttons on a portable device is just asking for butt dialing, but who said, "You know what would be a great physical accessory for our touch device? A DIAL." I mean how many uses does anybody have for a dial? I saw the example of a colour picker, but I never thought "Damn I need a dial because choosing from an RGB square was just too damn hard". I mean you could do volume? But there isn't any problems with volume rockers. It's just not needed and falls into my comment of pointless innovation.
Nobody needs what Microsoft is making, and what we do need, Microsoft tends to be doing a pretty shit job of making. Calling to my other post about EOL operating systems, a great consensus about operating systems is they stopped being good right around Windows 2000, XP if you have four hours of time to clean it up. Microsoft has somehow found a way to branch into many fields like gaming and hardware that nobody asked or wanted them to, fail at all of them, and on top of that, ruin the mainstream experience for everybody else.
I am just waiting for the day that software devs realize that if everybody took residence in Linux, Microsoft would loose any reason to exist.