A lot of the images in the manual have been over-compressed and look quite ugly imo, for example here: http://blender.org/manual/render/cycles/nodes/shaders.html
On the old wiki these images were fine: http://wiki.blender.org/index.php?title=Doc:2.6/Manual/Render/Cycles/Nodes/Shaders

@Greg Zaal (gregzaal) Informed me that this was done as a temporary measure while setting up the manual, and no one has gotten around to putting the old ones back yet.

I'd be willing to help with putting the old ones back if need be, but seems like there might be someone with easy access to the old and new images who might be able to do a quick automated fix for this?