I'm also a photographer in my spare time, and I'm looking forward to this device, in part because a friend of mine is an artist and she wanted me to evaluate it when it comes out to see if it's worth the money to her. The digitizer is definitely the biggest thing I want to test on the device. I'm hoping that the pen has pressure sensitivity, at least; and I'm hoping that it turns the screen off far enough from the screen that I can safely lift the pen a little bit before the touch screen turns back on again. Color accuracy will also be interesting; but, since it's an x86 device, I imagine we can install color correction software that will somewhat fix any issues there might be with that. (I have a very specific screen at home I use for color-accuracy. I'm very picky.)
I own a Surface RT, too, with a type cover and have experience using it for ... well, I got it the day it came out. First things first, I've worked with the device on my lap. I have pretty long legs, so the stand sits just fine in my lap; and, while I do prefer to have a hard surface underneath it, like a logitech or targus laptop stand, it's plenty usable in this situation. I use the machine on my lap at a friend's house on their futon all the time.
As for the "it's almost retina!" statement, the Surface Pro is going to be, for normal intents and purposes, retina at 17" away from your face(#). That's less than a normal laptop to face distance. For the Surface RT, I've personally find myself frequently having to raise the resolution of some webpages as they day goes on, because the text is too small to read. Using the same calculations as above, the Surface RT is "retina" at 23 inches.
