In the last few days I found (mostly on the FB group) a few interesting things that happened or are happening in Blender
1) Under revision, there's a GLSL shader node here https://developer.blender.org/D909 : «D909 Vector Transform node support for GLSL mode and the internal renderer»: this should allow us to start testing new approaches using the available version of GLSL (to be checked)
2) Again under revision, there's another node for BI, that can give other nodes information about the geometry, like position, normals, tanget, etc. https://developer.blender.org/D923 «D923 Cycles Geometry node support for Blender Internal»
It's quite likely that using this node will at least reduce and simplify the number of steps currently needed to obtain an NPR look from the BI render (currently, most setup spend a lot of nodes trying to undo some internal "photorealistic" computations the renderer does and then trying to apply a NPR algorithm using the recoveded data).
Moreover If these outputs can be used as inputs for the GLSL node, we could immediately be able to test some shader algorithms using GLSL, even if the available version will very likely be limited (about this: does the maximum language standard version depend on the currently used/initialized OpenGL context, or on the OpenGL version installed on the computer? I'll have to investigate on this).
3) Finally, an old post on graphicall.org (found by @blurymind) allows to download a version of Blender with a new modifier called "MOD_normaledit": this modifier allows to have one object use the normals taken from another object, something that could be VERY useful to get a decent-looking "anime shading" for character faces and maybe clothing, using a technique similar to what is shown in this Japanese language post, but using XSI: http://cveld.net/face-normal/
Windows version based on 2.71 here: http://www.graphicall.org/1125
Sources for the mentioned patches: https://drive.google.com/folderview?id=0B8btTTaJ0buXX2lncFdEV09ZMkU&usp=sharing#list
I applied the patch to a recent master of 2.72+ and it applies quite cleanly and the new modifier seems to do its job... even under Linux 64 bit.
Anyone interested in trying out these things or trying to follow the development/revision and run some tests?
I think I'm able to supply you with an Ubuntu Linux .deb file containing all 3 improvements... with a minimum of work.