*Update* - 2:30pm ET - It looks like BIS is slooooowly starting to come back to life. Some blackberry.net emails are coming through, but it looks like thats about it for now. A statement issued by RIM says they have isolated the issue, and are in the process of restoring email to all users.
The tip line is going to explode - it looks like BIS email is down for most carriers across the US and parts of Canada. No one is receiving email, but it appears that browser, BlackBerry Messenger, voice and SMS are still working however. No reports of exatcly when things went down or when they'll be up and running. Keep it here and we'll report anything as it pops up. Jump into the forums for more discussion.