I'm not treating it as it's stable, but it's what's going to be released as stable in a fairly short while given the Chrome release cadence. I was hoping that they were going to let this bake for a bit more before making it the default. This post makes it clear that they aren't going to do that.
They don't seem to do a straight unstable -> stable path. I'm not completely sure, but I'm pretty sure I've seen features stay in unstable while stable releases keep happening.
I'm totally fine using unstable, thanks. The point is that this particular feature is going to be enabled by default in Chrome 35 on Linux, as per the submitted article. That's not going to be 6 months from now. What happens with unstable features in the general case isn't particularly relevant when we know what the plan is with this specific case.
This is not a launch. You are running the UNSTABLE build. What do you expect?
Stop treating unstable and testing software like it's stable. The clue is in the name.