This is relevant for customers who have large numbers of templates per site. It might be a a useful feature to be able to organize templates by folders for easy, quick access.
This is especially true for CMS customers migrating to CM1 who are used to using folders to organize large quantities of templates.
I agree that this would be a good idea. But don’t forget that you can also add “thumbnail” images to the web_resources\templateImages directory which will help identify templates for contributors and Designers.
Thumbnail feature is awesome. For a lot of templates though, there are structural differences that are not obvious in the thumbnails.
This is planned, and will extend the current “Design” node in the Finder where today you see themes and web_resources files. We’ll also be adding a more automated thumbnail mechanism so the template thumbnail will actually change to match the current design of the template.
The target release number is not yet set for these enhancements.
I would really love this. Right now, what I do is put Z-Do-Not-Use as the first part of the template name so they are all the way at the end of the list. 
I’ve included a screen shot