Yeah, I have to explicitly allow it, that's awfully nice of them. But how long will opting out last when the advertisers realize they can force a few more eyeballs?

You realise that it's the browser vendor that decides this, not the website, right? Do you think it's only a matter of time before browsers remove their popup blockers as well?

It's also opt-in, not opt-out. The system doesn't work unless the user grants permission. It doesn't work automatically until the user switches it off.