According to the status page
Update - We are continuing to investigate this issue. Aug 31, 11:59 PDT
Update - We have been able to identify that logins are failing and most web pages are unavailable. We are continuing to work on this. Please watch this blog for updates. Aug 31, 11:44 PDT
Investigating - We are currently seeing intermittent issues with Profiles, Marketplace, and Log ins, and we are currently investigating this. Please watch this blog for updates. Aug 31, 11:14 PDT