Pencil seems like an fairly interesting idea, but it's priced in a really odd way. The $50 price point puts it well out of reach consumer and hobbyist users. Despite this, Pencil and Paper are not as robust as, nor ate they priced comparably to, professional digital drawing tools like Wacom's system.
Pencil precludes the casual demographic who just wants to doodle in their free time or take notes with its high price, but does not cater to the group of elite professionals who would be willing to cough up a substantial amount of money for drawing tools.
I just don't understand who this is for.