I was just thinking of the implications with importing CVS files, all the other uses mentioned would be very handy. I hadn't realized that this plugin would let us create lists from websites, what a time saver.
For example, when I find an author new to me, I'll go to their website first for their backlist. Amazingly many authors don't list their backlist or haven't updated their website in years. So, then I start compiling titles from research done with Goodreads and Library Thing, supplemented by fictfact and fantastic fiction. Usually calibre author profile open on one side of the screen and the pertinent website on the other side as I type away in calibre.
I'm brain-dead at the moment, so I can't think of many compilation websites except those mentioned above. Here's a few individual author sites that come to mind as I remember typing lots of their books into calibre.
Some really nice authors have downloadable lists, thank you JD Robb, but many only have titles and images. I'm assuming that if I wanted to import from a website and that if book data couldn't pulled by the plugin, that the plugin would just give an error message, so that I would know that manual entry was needed.