That is true.
Every time I looked into working on the exporter when I had time, blender API changes confused me a little. In fact the Api docs for vertex color in 2.62.0 seems to be different again. Yet from testing, nothing has changed yet.
I'm very confused.
Talking about that, it baffles me that blender doesn't have alpha in their vertex colors yet!
It's the year 2012 and they still lack of that. 3dsMAX had it decades ago. I wonder why it's taking them so long to get this right. Also, blender doesn't allow custom vertex normal assignment. You could apply them through script, but I'm not too sure it reflects in the mesh. Though I'm pretty sure they reset and recalculates them once you enter edit mode. This kinda sucks for real-time graphics where we want to perturb normals the "wrong" way to give fluffy result to a polygon soup. (Very useful for stuffs like bushes and trees)
So I'm actually thinking to have some sort of new way to support alpha and custom vertex normal.Vertex Alpha Support:
have color layers named "blah_alpha" to be the alpha layer of "blah".Custom Normal Support: have color layers named "_norms" to be applied as custom normals.
P.S. On second thought, if blender allows perturbing normals and doesn't recalculate the vertex normal as long as we don't edit it, maybe that should be safe enough to assume we do not need to support custom vertex normal channel. I'd imagine the only time we would ever deal with perturb normals is to generate them by ways of copying normals from another blob mesh instead of manually editing each normals by hand. This means generation of the normals should always be done after we are happy with the mesh and will not be modifying anymore.
Anyways, I'm pretty close to getting a basic mesh.xml file exported. I've just managed to extract blender's mesh info into proper Ogre ready structure.