Yip we have many users affected, according to MSOL service health page:
Exchange Online
Incident EX3022
Incident start time: Apr 23, 2013 8:30 AM
Date and time
Status
Details
Apr 23, 2013 9:05 AM
Investigating
We are investigating a service alert. At this time we don't have enough information to identify whether this is an actual service incident. We will provide more information shortly.