It's not a matter of "balls", it's a matter of being able to make a case that you'll block progress for everybody if you don't get an opt-out. Although Denmark might join after all, now (the ironic part is that since they float their currency against the euro unlike Sweden, adopting the euro would be a far smaller change for them than for Sweden).

So no, Sweden still has to join in principle - de facto they can join or not join as they like, but since in principle they have to join, you get absurdities like listing them in the assessed countries here.

Our public opinion was rather pro-euro. As a small country with lots of export and with lots of traveling abroad, people liked the economic advantages as well as the practicality of not having to carry around three or four wallets with different currencies when going on a holiday to Italy or Switzerland (though obviously for Switzerland you still need the one foreign currency). And we're not that nationalistic that people cared all that much about giving up the national currency.