It appears that you can not move components around from within 3D view but strangely enough you can be in 3D view and drag components from the library into positions. Those components can then be moved around until you switch back to 2D. Now if you switch to 3D again the components can not be moved. Seems a small qwerk of the feature crippling?
Might be a useful feature for positioning components in 3D to get a feel for a board layout.