I’m not sure this is a specific programming choice of sorts or if there is any reason for it, but why is Bone.roll not a thing while edit_bone.roll is a thing?
https://docs.blender.org/api/blender_python_api_2_67_1/bpy.types.Bone.html#bpy.types.Bone
VS
https://docs.blender.org/api/blender_python_api_2_67_1/bpy.types.EditBone.html
I’m sure that accessing the specific value is simple enough, however it would be nice not to have to go poking around and changing bone mode to get a read only value output.