Theme preview and active theme name display

It would be great to have a preview window when switching themes, where you can select the available themes that have been downloaded and see a quick preview of the theme before applying the theme to the dashboard. Having to go through every theme and applying is rather tedious, and often the names are obscure and don't give any idea about the colour palette.

It would also be great to be able to see what theme is currently being used on the dashboard, so that you know which one to use again for another time.