With Opera 12.11 out of the way, the team is already working on its follow-up, obviously called Opera 12.12. As its predecessor, Opera 12.12 is an incremental update designed to fix existing issues and nothing more.
The first snapshot, designed for developers, testers and really bored/eager users, is available for download.
As such, it should be relatively safe to play with – which is good, but it's not going to be that exciting since there's nothing new from Opera 12.11 or Opera 12.10 for that matter – which is less good.
A full-screen bug has been fixed, exiting the browser while in full screen resulted in a messed up UI at the next start. A crash in the Octane benchmarking suite has been fixed, as well as a memory leak related to SVG files.