Installed 2.0 last night.
Seems the install SQL is messed up. Only by luck did I figure it out.
The password set during install is written to the email field. ?? The admin username set during install is also set at the password.
So instead of logging into admin with "admin" "password", I had to use "admin", "admin".
I was able to update my email and password from within admin so that part is working fine.