In NGG 1.0.1, you can now include a caption for single pics as
[ singlepic id=x w=width h=height float=somefloat ]caption[/singlepic]
The problem is that the caption doesn't match the float, so a centered image gets a caption that is left-floated. Can the default NGG styles be updated to include classes that style the caption for the supported floats? That way it would be easy for users to customize them further.