Clean install of the beta. Attempt to set up as a new user.
iCloud says you must install 1PW on one other device. I have it on OS X 4.2.BETA-8 (420008).
Change the sync method on OS X to Dropbox and wait for sync to complete. Reinstall and attempt to set up as a new user. Select Dropbox as the sync method. Successfully allow use. Select the right keychain and it never gets out of "Retrieving encryption keys ...".
I haven't tried WiFi yet.