Xbox Live is down for some (updated: resolved)

Update at 2:0 p.m. Pacific: Microsoft has resolved the issue, noting on its status page that the core services for Xbox Live are working normally. The original story follows below.
You might have some trouble connecting online with your Xbox One today.
Xbox Live’s core services — which includes signing into or managing an account — are experiencing errors today, causing some users to be unable to log in. This includes those who pay for the $60-a-year premium Xbox Live