Government of Wales Bill

I am interested to see that a new constitutional principle is arising whereby one of the devolved assemblies can decide whether it wants further legislative powers. I also think that a constitutional glass ceiling is probably in place, because the Scotland Act is clear that the Scottish Parliament could not legislate to go beyond a devolved parliament status. I of course hope that the Minister will tell me that I am wrong and that the Scottish Parliament could start such negotiations for progress beyond a devolved parliament, but I am interested to see that the Government are now allowing a devolved institution to decide that it wants more powers and to generate a referendum, up to the point of devolution but not beyond.