I have read previous questions about the message being self-sufficient... but it really isn't. Even moderators are in the dark, and the message given reads like a generic error.
Suggestion: Add a link to some help section stating
Why are Accounts are temporarily unavailable?
There is a known outage occurring currently, the account list will be available soon.
Or something to the sorts.
Power-down of our Oregon data center is starting, if you see any issues we actually appreciate you yelling at us :)