Well you've basically figured it out already - Google have plans to add support for local file access in web apps, which might turn up some time early next year. By that point virtually everything that previously could only be done in the desktop download will be possible in the browser. Then there's no real justification for having a separate desktop download, so we'd probably retire the desktop download. This would reduce a lot of the maintenance overhead (since there's a bunch of desktop-specific code to handle things like folder saves, clipboard access etc. which we could remove, as well as eliminating the need for a parallel update process of the NW.js build used), and avoid NW.js specific issues such as various crash bugs that have come up lately that only affect NW.js.