I was wrong when I thought it was sorted, and I should have kept quiet. The 'new' EMR was definitely available a couple of hours ago (I have the special secret code to tell the difference!), but right now it's broken (all I'm getting is the home page of my old web host or an error message). I do not understand.
Anyway, you will know when - or if - things are up and running again, because you'll be able to see the picture in the sidebar (since the image resides over at EMR). Handy, that.
And, here we go: a few minutes later, it's back. I don't like this. I want stability, please. Is this sort of thing normal in the process of domain migration? Or is it something to worry about?