@ThylacineAlive this is true, it's the problem of having so many historic buildings. London still has a lot going for it and some great exhibits just I hope they are able to find a way to get around the listed building issues!
Who knows; maybe they want to empty out the Mappin Terraces in order to demolish or severely modify the area. Who knows what might happen...
What I wonder, though, is where will it be placed?