The issue was first reported at 12:20 p.m. PT. Zenprise diagnosed and tested issues on various networks to determine the cause of the outage. At 12:23 p.m. PT, Zenprise sent an email notification to its customers that BlackBerry service is down and the issue is with the BlackBerry network. Note: At about 12:30 p.m. PT, AT&T first learned there was a problem.
And straight from RIM…
* BlackBerry subscribers may be unable to send or receive messages. Subscribers may also be unable to register their device, roam in another location, or use other services such as Internet browsing.
* BlackBerry Internet Service subscribers may be unable to use the BlackBerry Internet Service web site or perform activities such as creating new accounts, accessing their internet mailbox, integrating third-party email accounts, or viewing email attachments.
* Devices may not receive new service books. BlackBerry Connect and BlackBerry-enabled devices that require a new PIN may be unable to receive the PIN.
* BlackBerry Enterprise Servers may be unable to connect to the BlackBerry Infrastructure.
* Wireless service providers and device resellers may be unable to use BlackBerry administration web sites or perform activities such as creating subscriber accounts or provisioning services for subscribers.
UPDATE: Judging by the deluge of delayed e-mails blinking away on my BlackBerry from last night, the problem looks resolved. Based on other reports, things started kicking back into gear between 7 and 8 PM last night. As for the reason, Jim Balsillie has stated that the outage was a result of a system upgrade.