Hi Chris,
There is not an update script yet for v2.0.0, partly because its a beta release. So far no obvious issues have been reported so if it stays like that, an update script will be available in two to three days. If you are planning to update, then we'll generate the new keys after the update, since they are different.
A clean install is also possible. I'll update a 200 appliance and post the steps required here. The simplest method will probably be to boot from a v2.0.0 USB drive, then run /etc/init.d/wanosd stop-all and copy the running image over with dd (dd if=/dev/sdb of=/dev/sda)
Let me test this first though and get back to you.