I would be trying out Opera 9 beta right about now, but it appears that the cookies bug described here has been made worse with Opera 9 Beta. The workaround no longer works at all.
I posted as much here. I’m hoping this gets fixed soon — I wasn’t surprised to see this in a technology preview, but it’s a little unnverving to see it in a beta. It’s a minor issue, but one that prevents me from trying it out.