A quick look at the docs and it doesn't yet support extensibility/plugins, though they say in the FAQ that they are working out a plan for that. Right now there is an external task runner that exposes the file name of the current buffer and some other data.

I look forward to seeing what they do on the plugin front. And hopefully they will be able to upstream performance changes to Electron and Atom and hopefully more.

Competition in the editor + dev tools space is always good.