Starting on 4/16, I powered on my Xbox to see I was not auto-signed in to Live. When I tried to sign in, I was asked for email and password, which I provided. I initially got an error code of 'incorrect email or password'. I then logged onto xbox.com to confirm my password, reset my password and tried again three times to the same result.
Then yesterday and today I do not get the wrong email/password message but "Sorry, there was a problem. Please try again later. Code: 80151011"
At first I thought this was due to my card expiring on my Music Pass account, for some reason. But I have updated that card and still no fix.