The latest browser update will, by default, notify the user about available updates in very much the same way Mozilla Firefox handles automatic patching.
From the changelog:
Users can specify that snapshot build releases of Opera should be downloaded by enabling "Download All Snapshots" in opera:config. Users can also choose not to check for updates or to automatically install updates by going to Tools > Preferences > Advanced > Security and changing the "Opera update level" (select box) to the: "Automatically install updates" setting.
The latest Opera update also adds support for TLS 1.2, a full set of padlock icons for security dialog box, and a new feature to handle anti-spoof checking.
It also fixes the following security problems.