Now that I'm looking for it, I see it's either still true in TS3 or else they've actually regressed with LN. Blotchiness and striation becomes more noticeable as you darken the textures. I'm beginning to think there may be some hard technical limitation that prevents dark colors from rendering well. Has anyone noticed similar problems in other games?
More likely due to the DR (Dynamic Range) limitations of the graphic card and/or monitor, in which case there isn't much that can be done about it. I have seen it in other games, even in DVD's while watching them, both on the computer and on the TV, although the issue is more prevalent and noticeable on the computer than the TV.
It is usually dark areas which cause the issue, although I have seen similar problems in very light areas as well, suggesting it is probably a rendering issue connected to DR capabilities, which at this time is hard to beat.
None of which explains why the books would go all fuzzy, of course. :p Unless they deliberately nerfed rendering quality across the board to compensate for the additional computing demands of running another EP.
I would hazard a guess that the books were never rendered to a high level of quality as they probably didn't envisage people zooming in so close to look at them. What you see in those shots is what is termed pixel peeping in photography, zooming in way beyond reasonable limits looking for problems which in reality are not actual problems.