We’re hearing a lot of reports that RIM’s BlackBerry network is down again. This isn’t confined to one carrier (we’re on AT&T and ours is a wrap). It looks as if Waterloo has acknowledged the issue, and classified it as a "critical severity outage". Not looking good. Let’s go, readers. Are you down for the count? If so, list your carrier!
UPDATE: Here is the officialness:
A component of the network infrastructure is experiencing a service interruption.
Service Affected: BlackBerry All service for some *The Americas Network (MULT) subscribers in the following locations: The Americas,
Summary: BlackBerry Network Infrastructure
Impact: 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. 
Ticket Number: BB90352
Incident Window Start Date and Time: 11 February 2008 15:20:00 (EST)
Downtime Duration: Ongoing
% of Subscribers Affected: 50.00 (estimated)
Cause: To Be Determined
EST = GMT – 5 hours
EDT = GMT – 4 hours
AEST = GMT + 10 hours"