UPDATE: Facebook reports the problem has been fixed. It's not just you. Facebook really is having trouble again.
The main problem seems to be that Facebook isn't loading a user's own stream of information. According to the DownRightNow Web site, Facebook started having trouble at approximately 10:30 Eastern Standard Time.
There have been numerous reports on Twitter and other sites of these and related problems. Officially, Facebook had nothing to say on its press page or its Twitter feed. A Facebook respresentative said after the firs hours that "Earlier today, we experienced an issue that prevented some people from loading Timeline or Pages content for a brief period of time. We resolved the issue quickly, and content is back to normal. We're sorry for any inconvenience we may have caused."
The problem appears to be with Facebook's internal integration of databases rather than a Distributed Denial of Service (DDoS) attack or any other external problem. We still don't know exactly what went wrong. This partial service disruption comes only a few weeks after a more serious Facebook outage.