Tim Caswell pushed an initial release of
WebApp Topcube, a framework for building desktop GUI apps with Node.js, to GitHub. The stated goal is to "Give node developers a way to have a desktop GUI to their node servers using HTML5 + CSS3 as the GUI platform."
It's still very early in the project's life - Caswell notes that he's not even sure he will continue developing it. WebApp is currently built on WebKitGTK+.
Caswell also has a GitHub repository for a project called node-gir, which he describes as:
Node-gir is node bindings to the girepository library making it possible to make automatic and dynamic calls to any library that has GI annotations installed.
This will make it possible to script a gnome desktop system entirely from node much in the way it's done today with Seed, GJS or pygtk.
Caswell works for HP on WebOS, and also runs HowtoNode.