I know that the update process is complicated and may run into issues (i.e. file or user permissions), but I think a one click update button in the admin interface would help with running the update. However, this is complicated by the way that Ghost installation process works (requiring a separate user and not really working under a generic, non-shell user, such as nginx or www-data or something similar).
Also, there is no clear indication in the admin interface when an update is required (a simple notification of some sort) or what current version you’re running (unless you click on the site name and then on the about Ghost link) and this could be easily fixed with a footer bar or a simple mention of the current Ghost version somewhere in the sidebar (above the view site link, which I would actually place somewhere at the top near the name of the site).
I think this is important mainly for security reasons and I’m glad that there is a ticket open for it:
Also, I would consider an auto update option (at least at command level via crontab, for example).