According to a statement from Research in Motion, the EMEA BlackBerry outage was caused by one of RIM’s European ISPs.

Our circuit provider is continuing to work to resolve the connectivity issue Identified on June 1st. As a result, the BlackBerry infrastructure will Remain in its current configuration until Further notice. Extensive service only after verification and testing have been completed Enterprise Traffic will be moved back onto the restored link. Our current target is During the maintenance window June 2nd from 9pm to 1am Eastern Time

No. Is Expected service impact at this time.

A future communication will be sent once the circuit provider has the connectivity issue RESOLVED.”
[Via BlackBerry Leaks]