Sarah. Repository management is something I have often called for from WordPress. It should be in core. Will it be? I doubt it. And so we see plugins and themes loading things over and over. Often, to avoid the conflicts, they ship identical versions but with renamed functions, classes etc. Just look how many times PrettyPhoto or FontAwesome gets loaded. Sometimes it is obvious as there is a distinct call to an external asset, but often the code gets rolled into bigger files, never to hbe dequeued. The system should be something like PHP pecl does. There should be a repository or register of all these assets, and WordPress, a plugin, or theme registers within that WordPress install that it needs asset x. The admin should be offered the choice where to source the assets from (local, private cdn, public cdn) and which version. The feature inside the WordPress admin would look like the plugin panel.