The local Boston Microsoft store has the Surface Pro on display, and I got a good solid 30+ minutes to play with it.
The Pro is definitely thicker than the Surface RT and even the iPad 1, but it's not to the point of feeling unattractive -- if anything it improves handling a little bit because it makes it nearer to the thickness of something like a book. I had no problem gripping the drive in portrait mode one-handed. (Being a widescreen device, it can get a little uncomfortable in landscape mode, but only if gripped from the sides. Top or bottom is just fine. Two handed is no problem at all.) The great thing about the Microsoft store is that they don't tether their devices down, so you can unplug it, pick it up, move around with it, really get a feel. That said, the weight, at 2 lbs, is no issue to me either. I have big hands, and I'm used to picking up heavy stuff for long periods of time (groceries etc) so I can't speak for everyone on that -- but if I owned the Pro, I'd have no qualms lugging it around in my camera bag. The system was warm from having been on all day and being used constantly, but -- it was only warm. Not a hot spot anywhere on it. There was the faintest warm breeze coming from the perimeter vent, (felt nice since my hands were frozen from the winter air.) Interestingly, the speakers were moved to blast sound out of the perimeter vent -- so unlike the RT, the Pro has no speaker holes. Clever.
Now, the thing you're REALLY curious about: The Pen. Yes, it works exactly like a Wacom pen. I forget if Microsoft has ever officially stated whether the digitizer and pen are made by Wacom or just liscened by Wacom, but the pen requires no power -- a misconception I had (I thought the pen recharged by docking with the Pro's power port.) The optically-bonded display is a real welcome change from the thick, elevated glass on my Cintiqs. When you put the pen to the screen, it really looks like you're physically touching the pixels. This makes pen calibration not only easier, but less necessary altogether -- the since there's very little to no parallax whatsoever between the cursor and pen tip, it will always be good to go.
The pen is responsive, MUCH more responsive than my old Thinkpad X201T. When I make a mark on a blank canvas, it follows up nearly as quickly as my Cintiq 12WX. Pressure sensitivity seems a little more smooth in its gradation than the old X201T as well, being able to maintain a lighter pressure more easily. (The X201T pen had such a short throw in its pen pressure, it would take almost no effort to go straight to 100%. Not so good.) The finish on the glass feels durable and totally smooth. The pen glides across without any feeling of resistance or thinking "I am going to make a scratch sooner or later...." The Pro recognizes the pen from an impressive distance above the screen, about as much as a Cintiq, which is great for making sure palm-rejection works properly. Sketching around in SketchBook Pro, I only had one instance where my palm left a little mark on the canvas because I brought my hand down at a weird angle. But otherwise, I had my hand resting all over the thing and it rejected just about everything except the pen input. The pen cursor will drift from the pen a LITTLE bit when brought close to the edges of the screen, but the effect is so little pronounced on the Pro compared to other traditional Tablet PC's. No cursor jitteryness -- beats out my Cintiq 12WX in that regard. The eraser tip wasn't programmed to work with pressure in SketchBook Pro, but it did switch to the Eraser tool at least. Not sure how I feel about the squared-off eraser, seems quite a bit inaccurate (due to its shape) compared to Wacom erasers, but it was mostly designed with note-taking in mind. I think if I owned a Pro, I'd be switching to the eraser tool rather than flipping the pen over. The pen can also enact Windows 8 gestures, such as swipe from the left or right to switch apps or access the trinkets drawer. This is a problem, because if you're making a line from one side of the screen, it's way to easy to suddenly fling yourself into a different app entirely. I'd have to see if there are ways to prevent that from happening.
Oh also, the button on the pen is that black stump that locks into the Pro's charge port. It's big and easy to press, very nice, didn't know that was a button from pictures.
The Pro's display is very nice. The Microsoft store is extremely bright inside, so the Pro felt a LITTLE sub-par in brightness, but I couldn't really tell since it's like... close to daylight in there. Colors seemed natural and neutral, not overly punchy. The 1920x1080 resolution is really something on a screen that size (running a real full desktop OS.) Yes, all of your desktop apps do run in full 1080p real estate size if you don't bump up the system UI Scale. Unscaled, text is ridiculously tiny (but so crisp!) If you have good eyesight, this won't bother you, you'll probably love the way it renders text at such a small size. But, if you want things to be a little more natural, you can up the scale to 25% or 50% larger. 50% larger will make all UI elements and web pages about how they appear on the 720p Surface RT. I found the best middle-ground to be the 25% larger, where things felt a little less microscopic, but extremely roomy given the screen size. Internet Explorer was easy to use with touch and was extremely smooth -- (actually EVERYTHING was really snappy and smooth. Music, video, maps, IE, Sketchbook Pro, whatever you're doing,) -- the system seems more than capable of dishing out performance for artists.
It goes to sleep and wakes up nearly as fast as the RT -- about as fast as an iPad that's been asleep for a few hours. So it's definitely a device that you can turn on and off as you please and no feel annoyed that you'll have to wait through log-on screens and reloading the desktop and such.
Some things I'm going to have to wait to see more about: the potential storage issues (though there IS an onboard MiniSD slot,) how well it might be able to handle some light gaming, and potentially maybe even some quick video editing.