Brush Classes should be able to be registered dynamically and in one place.
Registration should have 1 type of naming system (Alias System?) instead of the long and the short name.

An idea that came to my mind (haven't thought about pros/cons/problems yet): Have some kind of brush manager go through all loaded classes regularly and interpret every class with a special annotation as a brush. Register all new classes and eventually compare versions. -- This would also allow some kind of runtime patching (not sure how useful it would be though :P )
Also, I'm not sure how fast/slow this would be.