Sadly, there is probably not going to be any easy solutions.
Better instructions: not everyone speaks the language. Not everyone listens. Not everyone agrees with what they hear (as evidenced by this thread!).
Punishments: yeah, but how many of the passengers are going to be informed about that, and even if they are, is it going to influence what they do in a panic situation?
Locked bins: I'm quite certain that there'd be a long line because people are trying to get the bins open.
Recertification: maybe, but I'm not sure the world as a whole is ready to take a financial hit at least not until a sizable number of people die from this problem. So far that hasn't happened, mind you.
Maybe the best thing is indeed what XLA2008 suggested, asking the luggage people to stay onboard while the rest of us exit
but see above, in an emergency the passengers wouldn't obey/remember and none of this can't be enforced.
I think what might actually be useful is some minor adjustment in the flow areas for exits -- taking off a seat here and there to make sure there's ample space to exit. But again, not sure if we're ready to bear the cost.
Another thing that I personally very much wish would happen is prohibit the bulk roll-ons. There's really no reason for them, and they are already making a mess in regular operations, see how long boarding takes when people toil around with their oversize roll-ons.
Finally, I'd personally prefer to see not the locked bins solution but the pyrotechnic bin ejection solution. "Ladies and gentleman, the plane is burning, please evacuate. For your convenience, your MacBooks and roll-ons have already been ejected well clear of the airplane. Have a nice day."