This would be great for web apps that focus on teaching how to code with fun and interactive web editor. It can also be a great learning tool for creating projects that run your python code on a browser and document your progress as you go. I can see many interesting implementations for Skulpt. The simplest use case can be code sharing.
There have been various other projects already developed using Skulpt. Feel free to visit their website and browse through the projects gallery.
Skulpt is python for client side. No preprocessing, plugins or server-side support required, just write Python and reload.