About 3 hours ago I started getting prompted to enter my "correct" iCloud password. The message displayed contends that my password (previously and subsequently entered) is incorrect. This is in spite of the fact that I know its correct, and going to Settings > iCloud indicated that I am logged in properly. Likewise, I can also log into iCloud.com using my Apple ID and the known password. The popups prompting for the password come about every 20 minutes or so. I am running the Yosemite GM candidate 2.