Thanks so much for this rundown on tablet painting and for reminding us that tablets are supposed to replace paper. I think they will replace paper in more ways than they currently do, quite soon.
I'm not an artist, but I am curious. How do iPads etc., compare with Wacom's Cintiq or pressure sensitive tablets? Can an iPad or Android tablet, with a 'brush stylus' totally replace them, if the tablet is used as a painting peripheral? If more is needed, what is it? If little separates the two types of tablet for PC/Mac painting, I suspect that the Cintiq's days are numbered.
Who knows what the primary digital painting machine will be in the future - I doubt it will remain what it has been.