Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1500.20 Safari/537.36 OPR/15.0.1147.18 (Edition Next)
となっています。
アップデートストリームについては: Opera Features and the Release Cycle と言うことで、
Opera Developer: Most unstable, all the cool stuff Opera Next: The work we are stabilizing for the next final version Opera (Stable): The most stable build for everyone
Opera のエクステンションについて書かれている 〜
Major changes in Opera's extensions infrastructure
http://dev.opera.com/articles/view/major-changes-in-operas-extensions-infrastructure/
Ctrl+Insert, Shift+Insert hotkeys work in address bar
Ctrl+Shift+V does "paste and go"
Maximized window state saved on Windows, too
Chromium updated to 1500.52
>But we understand that removing bookmarks entirely for the people who actively use them is a big change, so we are going to build bookmarking functionality as a priority.
ブックマーク復活するらしい(苦笑)。