All is good. I was still dropping cookies with my own code and that seemed to be messing things up.
One thing to add to the docs is to make sure to move all of your themes over to the new system before accessing it.
Oh, one more thing, none of my profile information was moved over during the upgrade. My name, password, email.. that was all moved, but the other stuff About Me, Location, Home page.. all those things seem to be missing from my profile on the upgraded site....